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Anomeric Spirocycles by Solvent Incorporation: Reactions of O-Peracylated (Glyculopyranose and Glyculopyranosyl Bromide)onamide Derivatives with Ketones

Páhi, András; Czifrák, Katalin; Kövér, Katalin, E.; Somsák, László

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Ou e e ence: CAR 6720 P-au ho que y- 11 AUTHOR QUERY FORM Jou nal: CAR A icle Numbe : 6720 Please e-mail o ax you esponses and any co ec ions o: E-mail: co ec ions.essd@else ie .sps.co.in Fax: +31 2048 52799 Dea Au ho , Please check you p oo ca e ully and ma k all co ec ions a he app op ia e place in he p oo (e.g., by using on-sc een anno a ion in he PDF file) o compile hem in a sepa a e lis . No e: i you op o anno a e he file wi h so wa e o he han Adobe Reade hen please also highligh he app op ia e place in he PDF file. To ensu e as publica ion o you pape please e u n you co ec ions wi hin 48 hou s. Fo co ec ion o e ision o any a wo k, please consul h p://www.else ie .com/a wo kins uc ions. Any que ies o ema ks ha ha e a isen du ing he p ocessing o you manusc ip a e lis ed below and highligh ed by flags in he p oo . Click on he ‘Q’ link o go o he loca ion in he p oo . Loca ion in a icle Que y / Rema k: click on he Q link o go Please inse you eply o co ec ion a he co esponding line in he p oo Q1 Please con i m ha gi en name(s) and su name(s) ha e been iden i ied co ec ly. Q2 Please check he sen ence ‘As... ied’ o cla i y, and co ec i necessa y. Q3 Please check he usage o he e m ‘spli ed esonances’ in he sen ence ‘P o on...3)’, and co ec i necessa y. Q4 Please p o ide publishe de ails o Re . 16. Q5 Please speci y he signi icance o oo no e ‘⁄’ ci ed in Table 1, as a co esponding oo no e ex has no been p o ided. Thank you o you assis ance. Please check his box i you ha e no co ec ions o make o he PDF ile G aphical abs ac pp xxx–xxxAnome ic spi ocycles by sol en inco po a ion: eac ions o O-pe acyla ed (glyculopy anose and glyculopy anosyl b omide)onamide de i a i es wi h ke ones And ás Páhi, Ka alin Czi ák, Ka alin E. Kö é , László Somsák * O B CONH 2 (AcylO) n O OH CONH 2 (AcylO) n O (AcylO) n O OO (AcylO) n OO R 1 R 2 R 1 R 2 HN NH O (AcylO) n ONH R 1 R 2 O R 1 R 2 O (as sol en ) Ag(I) sal R 1 R 2 O (5 equi o as sol en ) H + + majo mino con igu a ions: D -gluco, D -galac o CAR 6720 No. o Pages 1, Model 5G 13 Ap il 2014 Highligh s Ke one inco po a ion eac ions. P epa a ion o glycopy anosylidene-spi o-(4-imino-1,3-dioxolanes). P epa a ion o glycopy anosylidene- spi o-(oxazolidin-4-ones). 1 Anome ic spi ocycles by sol en inco po a ion: eac ions o O-pe acyla ed (glyculopy anose and glyculopy anosyl b omide) onamide de i a i es wi h ke ones And ás Páhi a ,Ka alin Czi ák a ,Ka alin E. Kö é b ,László Somsák a, ⇑ a Depa men o O ganic Chemis y, Uni e si y o Deb ecen, POB 20, H-4010 Deb ecen, Hunga y 10 b Depa men o Ino ganic and Analy ical Chemis y, Uni e si y o Deb ecen, POB 21, H-4010 Deb ecen, Hunga y a icle in o A icle his o y: Recei ed 13 Ma ch 2014 Recei ed in e ised o m 31 Ma ch 2014 Accep ed 1 Ap il 2014 20 A ailable online xxxx Keywo ds: Sol en inco po a ion Spi o compounds Anome ic spi ocycles 4-Imino-1,3-dioxolanes Oxazolidin-4-ones abs ac Reac ions o O-pe ace yla ed ( a -D-galac o-hep ulopy anosyl b omide)onamide and O-pe benzoyla ed ( a -D-gluco-hep ulopy anosyl b omide)onamide wi h ke ones in he p esence o sil e (I) sal p omo e s ga e he co esponding O-pe acyla ed 1 0 ,5 0 -anhyd o-D-glyci ol-spi o-[1 0 ,5]-4-imino-2,2-disubs i u ed- 1,3-dioxolanes. The D-galac o configu ed s a ing compounds u nished bo h spi o epime s, while he D-gluco coun e pa s yielded only configu a ionally in e ed p oduc s. Unde acidic condi ions, O-pe benzoyla ed a -D-gluco-hep ulopy anosonamide and ke ones yielded he p o ec ed 1 0 ,5 0 -anhyd o- D-gluci ol-spi o-[1 0 ,5]-2,2-disubs i u ed-oxazolidin-4-ones, which we e O-debenzoyla ed by he Zemplén p o ocol. These compounds had no inhibi ion agains abbi muscle glycogen phospho lyase b. Ó2014 Published by Else ie L d. 1. In oduc ion Spi ocyclic mo i s a e widesp ead among na u al p oduc s and syn he ic compounds, and o en exhibi in e es ing and use ul bio- logical ac i i ies. 1–3 Spi ocycles in ol ing he anome ic ca bon o monosaccha ide de i a i es a e also well known, and ha e been, among o he s, shown o possess an ipa asi ic, 4 an ibac e ial, an i- ungal, 5 an idiabe ic, 6 he bicide, 7 glycosidase 8–10 and glycogen phospho ylase 11 inhibi o y ac i i ies. Syn he ic s a egies o ob ain spi ocycles we e amply 50 e iewed, 1–3 and ing closu e o geminally disubs i u ed cyclic compounds we e highligh ed as one o se e al gene ally applied app oaches owa ds a ious spi o de i a i es. Following his p inciple o he p epa a ion o anome ic spi ocycles he neces- sa y s a ing compounds can be selec ed om monosaccha ides homo- o he e obi unc ionalized a he anome ic cen e. 1 The la - e ype p ecu so s a e ep esen ed among o he s by de i a i es o ulose ype suga s u ilized, o example, o he syn heses o many so s o spi onucleosides. 12 In his line we epo ed he ans o ma- ions o (glyculopy anosyl b omide)onic acid de i a i es 13 60 o glycopy anosylidene-spi o-( hio)hydan oins, 14,15 - hiazolidinon- es, 16 and -oxazolines, 17 as well as ha o (glyculopy anosyl hiocyana e)ononi iles o glycopy anosylidene-spi o- hiazolines. 18 Some yea s ago we obse ed ha on gene a ion o he co e- sponding glycosylium ion om (glyculopy anosyl b omide)ona- mides (e.g., 1)by Ag 2 CO 3 in ace one spi o-imino-dioxolanes 2a and 3a (Table 1) we e o med by inco po a ion o he sol en . 19 This eac ion can be ega ded as a di ec O-glycosyla ion o a ke one which is a e y a e ans o ma ion: o ma ion o ace al gly- cosides in he p esence o ke ones was desc ibed om O-pe ace y- 70 la ed N-(2,4-dini ophenyl)- a - D -glucosaminyl b omide (bu no om ace ob omoglucose), 20 TMS-glycosides 21,22 and O-pe benzy- la ed 1- hioglycosides. 23 Fo mal glycosyla ion o ke ones by a spe- cial in amolecula aglycon deli e y was ecen ly epo ed. 24 In his pape ull expe imen al de ails a e epo ed o he ex ension o he abo e ke one inco po a ion in eac ions o (glycu- lopy anosyl b omide)onamides. Fu he mo e, s udies on he eac- ions o (glyculopy anose)onamides and ke ones as well as de ailed s uc u al elucida ion o he compounds a e also desc ibed. 80 2. Resul s and discussion Following he fi s obse a ion 19 on inco po a ion o ace one in o he p oduc s in he eac ion o 1(Table 1,en y 1) in he p es- ence o Ag 2 CO 3 , he applicabili y o o he ke ones and p omo e s h p://dx.doi.o g/10.1016/j.ca es.2014.04.003 0008-6215/Ó2014 Published by Else ie L d. ⇑ Co esponding au ho . Tel.: +36 52512900x22348; ax: +36 52512744. E-mail add ess: [email p o ec ed] (L. Somsák). 1 S ic ly speaking hese compounds migh no mo e ha e a ‘ eal’ anome ic, ha is, an ace al ype ca bon in many cases, howe e , o he sake o simplici y his e m will be used he e. Q1 Ca bohyd a e Resea ch xxx (2014) xxx–xxx Con en s lis s a ailable a ScienceDi ec Ca bohyd a e Resea ch jou nal homepage: www.else ie .com/loca e/ca es CAR 6720 No. o Pages 11, Model 5G 15 Ap il 2014 Please ci e his a icle in p ess as: Páhi, A.; e al. Ca bohyd . Res. (2014), h p://dx.doi.o g/10.1016/j.ca es.2014.04.003 we e in es iga ed. Wi h bu anone bo h Ag 2 CO 3 and AgOT ga e simila esul s (en ies 2 and 3) expec edly u nishing he spi o- dioxolanes 2b and 3b as insepa able dias e eome ic mix u es. Symme ical ke ones (en ies 4–6) also ga e he spi o-epime s 2c–e as he main p oduc s whe eby 3c–e could be isola ed in much lowe yields. F om each eac ion mix u e he hyd oly ic p oduc 4 90 could be isola ed in 25–38% yields. Simila eac ions o he D -gluco configu ed 5a e collec ed in Table 2. Compa isons o en ies 1, 3and 5 wi h en ies 2, 4and 6, espec i ely, show ha he use o AgOT is supe io o ha o Ag 2 CO 3 in e ms o eac ion imes, al hough he highe e ficiency o he o me is no always eflec ed in he yields. In hese eac- ions o 5only spi o-epime 6was obse ed in he eac ion mix- u es (besides he hyd olyis p oduc 7). A emp s o educe he amoun o he ke ones o 5–10 equi in ni ome hane as he sol en p o ed unsucces ul, and he only 100 p oduc s o be obse ed we e 4and 7. T ials o use aldehydes as he ca bonyl eagen s esul ed in mul icomponen mix u es om which no disc e e p oduc s could be isola ed. Reac ions o ( D -gluco-hep -2-ulopy anose)onamide 7wi h ke- ones we e in es iga ed nex (Table 3). As in simila cycliza ions o non-ca bohyd a e a -hyd oxy-ca boxamides p- oluenesul onic acid (pTSA) was equen ly applied o p omo e he ans o ma- ion 25 his acid was ied fi s . Howe e , no eac ion o 7could be obse ed wi h ace one as he sol en in he p esence o ei he ca aly ic o s oichiome ic amoun s o pTSA. On he o he hand, 110 ca aly ic iflic acid (T OH) elici ed he eac ion (en y 1), and ais- ing i s amoun o one equi alen significan ly inc eased he yield o 8a (en y 2). Unde he same condi ions bu anone ga e an insepa- able dias e eome ic mix u e o 8b (en y 3). The amoun o he ke- one could be diminished o 5 equi , and bo h THF and oluene p o ed sui able sol en s o p epa e 8c– in good yields (en ies 4–7). In hese eac ions o ma ion o one compound was obse ed in each case (dis ega ding dias e ome s 8b). Reac ions wi h alde- hydes ga e only decomposi ion p oduc s. Spi o-oxazolidinones 8we e O-debenzoyla ed by he Zempén 120 p o ocol o gi e compounds 9in e y good yields. These de i a- i es we e es ed as possible inhibi o s o abbi muscle glycogen phospho ylase b, howe e , showed no inhibi ion up o 625 l M concen a ion. S uc u al elucida ion o he p oduc s ( ollowing he mass spec- ome ic de e mina ion o he molecula masses) was ca ied ou by NMR me hods as illus a ed o he compounds depic ed in Figu e 1(see also Table 4 o selec ed NMR da a o he compounds). P o on spec a showed spli ed esonances o a py anoid ing in he 4 C 1 con o ma ion as well as he expec ed signals o he ali- 130 pha ic pa s and he p esence o an exchangable p o on assigned as an NH o each compound (see de ails in Sec ion 3). The ca bon spec a con ained (besides he expec ed esonances o he suga ing, he acyl p o ec ing g oups and he alipha ic moie ies) signals o h ee ca bons wi h no a ached hyd ogens. Those in he ange o 99.9–100.7 ppm we e assigned as he C-[1 0 ,5] spi o cen es. Resonances o 112.5–122.2 and 158.2–160.9 ppm (clea ly dis inc om he C@O esonances o he p o ec i e g oups) we e indica i e o ace al and imida e ype ca bons, espec i ely, in compounds 2,3 and 6. On he con a y, he spec a o compounds 8exhibi ed Table 1 Reac ion o O-pe ace yla ed ( a -D-galac o-hep ulopy anosyl b omide)onamide (1) wi h ke ones O AcO AcO AcO OAc B CO 1234 NH2 O AcO AcO AcO OAc O OO AcO AcO AcO OAc OO O AcO AcO AcO OAc OH CONH2 HN NH R1 R2 R1R2 R1R2 O as sol en p omo e ++ (1 equi .) in he da k, unde A En y R 1 R 2 P omo e R. ime (d) Yield (%) 1a a Me Me Ag 2 CO 3 17145 2bMe E Ag 2 CO 3 649 bc c 3 AgOT 6 43 b 19 ⁄ 38 4cE E AgOT 3 32 14 27 5d–(CH 2 ) 4 – AgOT 6 48 T aces 26 6e–(CH 2 ) 5 – AgOT 2 44 8 25 a F om Re . 19. b Two dias e eome s. c Obse ed bu no isola ed. Table 2 Reac ion o O-pe benzoyla ed ( a -D-gluco-hep ulopy anosyl b omide)onamide (5) wi h ke ones O BzO BzO BzO OBz B CONH 2 R 1 R 2 O as sol en 1 equi . p omo e in he da k, unde A O BzO BzO BzO OBz O O HN R 1 R 2 O BzO BzO BzO OBz OH CONH 2 + 567 En y R 1 R 2 P omo e R. ime (d) Yield (%) 1aMe Me Ag 2 CO 3 11 17 41 2 AgOT 1 37 46 3cE E Ag 2 CO 3 20 5 34 4 AgOT 1 46 35 5d–(CH 2 ) 4 –Ag 2 CO 3 13 56 18 6e–(CH 2 ) 5 – AgOT 1 28 35 Q5 Q2 Q3 2A. Páhi e al. / Ca bohyd a e Resea ch xxx (2014) xxx–xxx CAR 6720 No. o Pages 11, Model 5G 15 Ap il 2014 Please ci e his a icle in p ess as: Páhi, A.; e al. Ca bohyd . Res. (2014), h p://dx.doi.o g/10.1016/j.ca es.2014.04.003 140 an addi ional signal in he ange o he benzoyl ca bonyls (162.4– 166.6 ppm) and om hese ha o he highes chemical shi was ( en a i ely) assigned o amide C-4. A esonance in he ange o 92.4–100.1 ppm could be a ibu ed o an aminal ype ca bon and his co obo a ed ha he ni ogen was in an endocyclic posi- ion in 8. To confi m he di e ence in he cons i u ion o he he - e ocyclic pa s o he spi ocycles, CMPG-HSQMBC expe imen s 26– 28 we e ca ied ou wi h 6a and 8e. In hese spec a c oss peaks (indica ed by as e isks in he o mulae o he espec i e com- pounds in Fig. 1) be ween NH and C-4 and C-5, bu no wi h C-2, 150 we e obse ed o 6a o u he p o e he imino-dioxolane s uc- u e. On he o he hand, c oss peaks be ween NH and C-2, C-4 and C-5, as well as wi h ca bons o he alipha ic subs i uen we e p esen o 8e o e i y he oxazolidinone ing. Fo 8e his mea- su emen also co obo a ed he chemical shi assignmen o amide C-4. The configu a ion o he spi o ca bons C-[1 0 ,5] was es ablished as R o 2and 6, and S o 3and 8based on he h ee bond he e onuclea coupling cons an s be ween H-2 and C-4 shown in Figu e 1indica ing he ans diaxial e sus gauche ela- ionships be ween he espec i e nuclei in he 4 C 1 con o ma ion 160 o he suga ing. Al hough hese couplings could no be measu ed o each compound due o insu ficien sample quan i ies, no doub was le abou he spi o configu a ion o he o he membe s o he se ies. Namely, he p o on esonances had cha ac e is ic shi s depending on he C-[1 0 ,5] configu a ion (c . Fig. 1 and Table 4): H-2 0 had a downfield shi o 0.1–0.2 ppm i he C@NH/C@O was on he same side o he py anoid ing; simila ly, downfield shi s we e obse ed o H-3 0 (0.7 ppm) and H-5 0 (0.4 ppm) when hey we e in he same si ua ion. Analogous 1 H chemical shi pa e ns we e obse ed ea lie o o he glycopy anosylidene- 170 spi o-he e ocycles. 14,15 Fo ma ion o spi ocycles 2,3and 6can be unde s ood by ollowing he mechanis ic p oposal in Scheme 1. The sil e sal p omo e acili a es he gene a ion o he co esponding glycosyli- umion B1 om 1o 5. Nucleophilic a ack o a ke one wi h anchi- me ic assis ance o he 2-O-acyl g oup (D1) may lead o ca boca ion A1 while wi hou neighbou ing g oup pa icipa ion he epime ic ca ion, ep esen ed by esonance o ms E1 and F1, can be o med. In amolecula a ack o he amide oxygen (illus- a ed in de ails o F1 only), he ha de pa o his unc ional g oup, H-5' O O O AcO AcO OAc HN E E H-3' H-2' AcO H-5' O O O AcO AcO OAc H-3' H-2' AcO NH E E 3JH-2',C-4 ~6.1Hz 3JH-2',C-4 ~2.1Hz 160.4 160.8 116.8 99.9 100.8 116.2 5.99 4.85 5.60 5.30 4.42 5.74 H-5' O O O BzO BzO OBz HN Me Me H-3' H-2' BzO 3JH-2',C-4 ~5.4Hz 160.5 112.8 100.3 6.80 5.13 5.85 H-5' O O NH BzO BzO OBz H-3' H-2' BzO O 3JH-2',C-4 ~2.5Hz 166.4 6.10 4.69 6.00 ** ** * * * ** * C oss peaks wi h NH in he spec a om CPMG-HSQMBC expe imen s. 100.1 93.5 37.6 (39.0) 39.0 (37.6) 2c 3c 6a 8e 2 4 4 2 2 4 4 2 1' 55 1' 1' 5 1' 5 Figu e 1. Rep esen a i e NMR da a o he s uc u al elucida ion o he new compounds. Table 3 Reac ion o 3,4,5,7- e a-O-benzoyl- a -D-gluco-hep ulopy anosonamide (5) wi h ke ones O BzO BzO BzO OBz OH CONH 2 R 1 R 2 O O BzO BzO BzO OBz ONH /T OH sol en , e lux o e nigh O R 2 R 1 O HO HO HO OH ONH O R 2 R 1 NaOMe MeOH, 78 9 En y R 1 R 2 Ke one (equi .) Sol en Acid (equi .) Yield (%) 1aMe Me As sol en — 0.1 58 94 2 As sol en — 1.0 89 3bMe E As sol en — 1.0 92 a 96 4cE E 5 THF 1.0 69 91 5d–(CH 2 ) 4 – 5 THF 1.0 86 91 6e–(CH 2 ) 5 – 5 Toluene 1.0 69 96 7 –(CH 2 ) 6 – 5 Toluene 1.0 71 77 a Two dias e eome s. A. Páhi e al. / Ca bohyd a e Resea ch xxx (2014) xxx–xxx 3 CAR 6720 No. o Pages 11, Model 5G 15 Ap il 2014 Please ci e his a icle in p ess as: Páhi, A.; e al. Ca bohyd . Res. (2014), h p://dx.doi.o g/10.1016/j.ca es.2014.04.003 180 may gi e he cyclized iminium ion C1. Dep o ona ion o his in e - media e and ha o he analogous one (no shown) de i ed om A1 gi e hen he isola ed p oduc s o e ained (3) and in e ed con- figu a ion (2), espec i ely. Fo ma ion o he by-p oduc s 4and 7 a e o be explained by he wa e con en o he sol en s a acking on glycosyliumion B1. The finding ha om he D -gluco configu ed 5only he o ma ion o 6was obse ed, 2 while 1o he D-galac o con- figu a ion ga e bo h epime s 2and 3, may be indica i e o a emo e pa icipa ion 29 o he axial 4-O-ace yl g oup o 1 acili a ing he o - ma ion o 3. 190 A mechanis ic p oposal o he o ma ion o spi ocycles 8 (Scheme 2) can be mo e complex since, due o he p esence o se - e al unc ional g oups whose p o ona ion may s a he eac ion, al e na i e pa hways may occu simul aneously. The fi s (mos emp ing) possibili y is he p o ona ion o he glycosidic OH in 7 ollowed by loss o wa e o gi e glycosyliumion C2 which is he same in e media e as B1 in Scheme 1. A ack o a ke one on C2 would gi e A2 (equal o in e media e F1 in Scheme 1), howe e , he o ma ion o he epime ic in e media e A1 (shown in Scheme 1) mus also be aken in o accoun . This possibili y ende s his pa h- 200 way less p obable since only he configu a ionally e ained epime 8was obse ed in he eac ions. Fo ma ion o A2 (wi hou epime - iza ion) should also be possible ia p o ona ion and subsequen dehyd a ion o a mixed hemike al E2 which can de elop om 7 by nucleophilic addi ion o he glycosidic OH o he ke one o i s p o ona ed o m D2. Ring closu e o A2 (=F1) occu ed by he nucleophilic a ack o he amide oxygen unde condi ions o Scheme 1 (c . F1?C1) o gi e he imino-dioxolanes 3, howe e , hese compounds we e no p esen in he eac ions o 7(Scheme 2). Conside ing he di e en eac ion condi ions his may aise 210 wo possibili ies: (i) imino-dioxolanes may be o med as p ima y Table 4 Selec ed NMR da a o he O-pe acyla ed compounds a 2,3,6and 8(d[ppm], J[Hz]) O AcO AcO AcO OAc O O HN R 1 R 2 1' 2' 3' 4' 5' 2 4 5 2a b 2b 2c 2d 2e H-2 0 5.58 5.54/5.59 5.60 5.57 5.57 H-3 0 6.00 6.05/5.89 5.99 5.98 6.01 H-5 0 4.88 4.75/4.85 4.85 4.84 4.85 C-[1 0 ,5] 100.4 100.2/100.3 99.9 100.1 100.1 C-2 112.6 114.7/114.1 116.8 116.2 113.2 C-4 160.9 160.4/160.2 160.4 158.8 158.2 3 J H-2 0 ,C-4 5.6 4.1 6.1 6.1 5.3 O AcO AcO AcO OAc OO NH R1R2 1' 2' 3' 4' 5' 2 4 5 3a b 3b 3c 3e H-2 0 5.74 5.74/5.69 5.74 5.75 H-3 0 5.25 5.35/5.20 5.30 5.26 H-5 0 4.41 4.43/4.39 4.42 4.41 C-[1 0 ,5] 100.3 100.9/100.9 100.8 100.8 C-2 112.5 114.8/113.8 116.2 113.1 C-4 161.2 160.2/160.2 160.8 160.3 3 J H-2 0 ,C-4 n.m. c n.m. c 2.1 n.m. c O BzO BzO BzO OBz O O HN R 1 R 2 1' 2' 3' 4' 5' 2 4 5 6a 6c 6d 6e H-2 0 5.85 5.92 5.87 5.87 H-3 0 6.80 6.82 6.82 6.82 H-5 0 5.13 5.13 5.12 5.14 C-[1 0 ,5] 100.3 99.9 99.9 99.8 C-2 112.8 116.6 122.2 113.5 C-4 160.5 160.6 160.3 160.4 3 J H-2 0 ,C-4 5.4 4.9 4.9 5.0 O BzO BzO BzO OBz ONH O R2 R1 1' 2' 3' 4' 5' 2 5 4 8a 8b 8c 8d 8e 8 H-2 0 5.96 5.99/5.97 6.00 5.97 6.00 5.98 H-3 0 6.09 6.10/6.09 6.10 6.08 6.10 6.08 H-5 0 4.66 4.63/4.63 4.64 4.63 4.69 4.66 H-4 0 5.73 5.72/5.71 5.70 5.73 5.71 5.70 C-[1 0 ,5] 100.5 100.3/100.35 100.2 100.7 100.1 100.1 C-2 92.4 94.9, 94.5 97.1 100.1 93.5 97.2 C-4 166.0 166.4/166.1 166.6 166.1 166.4 166.1 3 J H-2 0 ,C-4 n.m. c n.m c n.m c n.m. c 2.5 n.m. c a Fo subs i uen s R 1 and R 2 see he espec i e ables (Table 1 o 2and 3,Table 2 o 6, and Table 3 o 8). b Da a aken om Re . 19. c No measu ed because o insu ficien sample quan i y. 2 I is o be no ed ha om he ace yla ed coun e pa o 5 o ma ion o a e y mino amoun (6%) o he in e ed p oduc was epo ed. 19 4A. Páhi e al. / Ca bohyd a e Resea ch xxx (2014) xxx–xxx CAR 6720 No. o Pages 11, Model 5G 15 Ap il 2014 Please ci e his a icle in p ess as: Páhi, A.; e al. Ca bohyd . Res. (2014), h p://dx.doi.o g/10.1016/j.ca es.2014.04.003 p oduc s which hen gi e oxazolidinones 8in a p o on ca alysed equilib a ion; (ii) ing closu e akes place by a N-nucleophilic a - ack o he hyd oximide au ome o he amide moie y. The fi s possibili y was uled ou by an expe imen in which an imino- dioxolane 6was subjec ed o he condi ions o he o ma ion o 8. Thus, 6a was boiled in ace one in he p esence o T OH (1 equi ) o 24 h, howe e , no change could be de ec ed by TLC. The second possibili y can be easonable since au ome iza ion o amides un- de acidic condi ions (c . 7?F2?I2) is a known phenomenon. 30 220 Thus, A2 may ing-close o p o ona ed hyd oxy-oxazoline B2 which, a e dep o ona ion and au ome iza ion can gi e he isola ed 8. OCONH2 B RCO O O CONH2 RCO O OCONH2 RCO O O CONH2 O O R O CONH2 RCO O O RCO O NH2 O C1 B1A1 D1 E1 F1 Ag -AgB R1R2 O O R1R2 O R1R2 O RCOOO NH R1R2 O O RCOOO NH2 R1R2 O -H R2 R1 O R2 R1 O O ROCO O O HN R1 R2 R1R2 O R1R2 O Ag / Ag / 1o 5 2o 63 OCONH2 OH RCO O 4o 7 H2O Ag H2O Scheme 1. P oposed mechanism o he o ma ion o 1 0 ,5 0 -anhyd o- D -glyci ol-spi o-[1 0 ,5]-4-imino-1,3-dioxolanes 2,3, and 6. O CONH2 RCO O C2 (= B1 in Scheme 1) OCONH2 OH RCO O H O RCOONH O R1R2 O R1R2 OH O OH RCO O OH NH2 O OH RCO O OH NH R1R2 O O OH RCO O OH N H-H2O HO R2 R1 -H O RCOO HO N OH R1R2 -H au ome- isa ion 78 F2 H2 I2 J2 O RCO O OH N HO R2 R1 G2 O OH RCO O OH N R2 R1 K2 H -H2O + H -H2O OCONH2 O RCO O R1R2 OH OH R1R2 -H R1R2 O H -H2O O RCO O OH NH A2 (= F1 in Scheme 1, c A1 also) O R1R2 O RCOONH OH R1R2 O -H au ome- isa ion B2 E2 D2 Scheme 2. Possible mechanis ic pa hways o he o ma ion o 1 0 ,5 0 -anhyd o- D -gluci ol-spi o-[1 0 ,5]-oxazolidin-4-ones 8. A. Páhi e al. / Ca bohyd a e Resea ch xxx (2014) xxx–xxx 5 CAR 6720 No. o Pages 11, Model 5G 15 Ap il 2014 Please ci e his a icle in p ess as: Páhi, A.; e al. Ca bohyd . Res. (2014), h p://dx.doi.o g/10.1016/j.ca es.2014.04.003 Since a -hyd oxy-ca boxamides and ca bonyl compounds a e known o u nish oxazoles unde acidic condi ions, he gene ally ac- cep ed mechanism o he Fische oxazole syn hesis 25 should also be conside ed in he p esen ans o ma ion. P o ona ion o he amide oxygen o 7as shown in F2 may esul in a au ome iza ion 30 o gi e a leas a mino p opo ion o I2 which can a ack he ke one (o i s p o ona ed o mD2) as a N-nucleophile o gi ein e media e J2.P o- 230 ona iono ahyd oxylg oupinJ2 maylead oelimina iono wa e o p oduce ei he ca boca ion G2 o K2, bo h o which can ing close o H2 by he nucleophilic a ack o he emaining OH on he posi i ely cha ged ca bon. Due o he p esence o h ee elec on eleasing sub- s i uen s, ca boca ion K2 migh be mo e s able han glycosyliumion G2, he e o e, o ma ion o H2 ia K2 migh be p e e ed. This is also madelikely by he o ma iono a single isome o 8 ha would p ob- ably no be he case in ou e J2?G2?H2. Final dep o ona ion and au ome iza ion o H2 may hen yield he isolable p oduc 8. Inconclusion, he eac ions o (glyculopy anoseandglyculopy ano- 240 syl b omide)onamides wi h ke ones ga e access o he p epa a ion o new anome ic spi ocycles, namely, 1 0 ,5 0 -anhyd o- D -glyci ol- spi o-[1 0 ,5]-4-imino-2,2-disubs i u ed-dioxolanes and 1 0 ,5 0 -anhyd o- D -glyci ol-spi o-[1 0 ,5]-2,2-disubs i u ed-oxazolidin-4-ones. The s uc u es we e unambiguously assigned by NMR me hods. De ailed mechanisms we e p oposed o explain he o ma ion o bo h cons i u- ional isome s as well as he s e eoselec i i ies o he ing o ming eac ions. The spi o-oxazolidinones we e es ed agains abbi muscle glycogen phospho lyase b, howe e , had no inhibi o y e ec . 3. Expe imen al 250 3.1. Gene al me hods Mel ing poin s we e measu ed in open capilla y ubes o on a Kofle ho -s age and a e unco ec ed. Op ical o a ions we e de e - mined wi h a Pe kin–Elme 241 pola ime e a oom empe a u e. NMR spec a we e eco ded wi h B uke 200 (200:50 MHz o 1 H/ 13 C), B uke DRX 360 (360:90 MHz o 1 H/ 13 C) o A ance II 500 (500:125 MHz o 1 H/ 13 C) spec ome e s. Chemical shi s a e e e enced o Me 4 Si ( 1 H), o o he sol en signals o DSS in D 2 O ( 13 C). Mass spec a we e eco ded by a B uke mic OTOF-Q ins u- men . TLC was pe o med on DC-Alu olle Kieselgel 60 F 254 (Me ck), 260 and he pla es we e isualized unde UV ligh and by gen le hea - ing. Fo column ch oma og aphy Kieselgel 60 (Me ck, pa icle size 0.063–0.200 mm) was used. Dichlo ome hane was dis illed om P 4 O 10 and ace one om CaSO 4 ) and s o ed o e 4Å molecula sie es. O ganic solu ions we e d ied o e anhyd ous MgSO 4 and concen a ed unde diminished p essu e a 40–50 °C (wa e ba h). 3.2. Gene al p ocedu e I o he p epa a ion o O-pe acyla ed 1 0 ,5 0 -anhyd o- D -glyci ol-spi o-[1 0 ,5]-4-imino-2,2-disubs i u ed- 1,3-dioxolanes 2, 3 and 6 To a solu ion o an O-pe acyla ed (glyculopy anosyl b o- 270 mide)onamide 1 31 o 5 32 (0.50 g) in a d y ke one (5 mL) con aining molecula sie es (3 Å) Ag 2 CO 3 (1 equi ) o AgOT /E 3 N (1 equi ) was added. The mix u e was s i ed a in he da k unde A a mo- sphe e un il TLC (1:1 o 1:2 E OAc–hexane) showed comple e ans- o ma iono hes a ingma e ial.Then hemix u ewasfil e edona Celi e pad and he sol en emo ed unde diminished p essu e. The c ude p oduc was pu ified by column ch oma og aphy. 3.2.1. (1 0 R,2RS)- and (1 0 S,2RS)-2 0 ,3 0 ,4 0 ,6 0 - e a-O-ace yl-1 0 ,5 0 - anhyd o- D -galac i ol-spi o-[1 0 ,5]-2-e hyl-4-imino-2-me hyl- 1,3-dioxolanes (2b and 3b) 280 P epa ed om 1(0.50 g, 1.10 mmol) and bu anone in he p esence o AgOT acco ding o Gene al p ocedu e I (Sec ion 3.2). Column ch oma og aphy (1:1 E OAc–hexane) ga e h ee ac ions. F ac ion I: 0.21 g (43%) o an insepa able dias e eome ic mix u e o 2b as a colou less oil; R = 0.71 (1:1 E OAc–hexane). Cha ac e iza ion o dias e eome A: 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.40 (s, 1H, NH), 6.05 (dd, 1H, J 2 0 ,3 0 11.1 Hz, J 3 0 ,4 0 3.2 Hz, H-3 0 ), 5.54 (d, 1H, J 2 0 ,3 0 11.1 Hz, H-2 0 ), 5.51 (dd, 1H, J 3 0 ,4 0 3.2 Hz, J 4 0 ,5 0 1.0 Hz, H-4 0 ), 4.75 (ddd, 1H, J 5 0 ,6 0 a 6.8 Hz, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 1.0 Hz, H-5 0 ), 4.20–4.02 (m, 2H, H-6 0 a, H-6 0 b), 2.15, 2.05, 1.95, 290 1.93 (4s, 12H, OCOCH 3 ), 1.70 (q, 2H, J7.3 Hz, CH 2 CH 3 ), 1.35 (s, 3H, CH 3 ), 0.88 ( , 3H, J7.3 Hz, CH 2 CH 3 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 170.3, 170.0, 169.6, 169.3 (CO), 160.4 (C-4, 3 J H- 2 0 ,C-4 =4.1 Hz), 114.7 (C-2), 100.2 (C-1 0 ), 69.8, 68.8, 67.5, 66.9 (C- 2 0 –C-5 0 ), 61.3 (C-6 0 ), 33.4 (CH 2 CH 3 ), 25.6 (CH 3 ), 20.7, 20.5, 20.3, 20.2 (COCH 3 ); 6.9 (CH 2 CH 3 ). Cha ac e iza ion o dias e eome B: 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.40 (s, 1H, NH), 5.89 (dd, 1H, J 2 0 ,3 0 11.1 Hz, J 3 0 ,4 0 3.2 Hz, H-3 0 ), 5.59 (1H, d, J 2 0 ,3 0 11.1 Hz, H-2 0 ), 5.48 (dd, 1H, J 3 0 ,4 0 3.2 Hz, J 4 0 ,5 0 1.0 Hz, H-4 0 ), 4.85 (ddd, 1H, J 5 0 ,6 0 a 6.8 Hz, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 300 1.0 Hz, H-5 0 ), 4.20–4.02 (m, 2H, H-6 0 a, H-6 0 b), 2.16, 2.04, 1.98, 1.94 (4s, 12H, OCOCH 3 ), 1.85 (q, 2H, J7.3 Hz, CH 2 CH 3 ), 1.55 (s, 3H, CH 3 ), 0.96 ( , 3H, J7.3 Hz, CH 2 CH 3 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 170.2, 170.0, 169.8, 169.1 (CO), 160.2 (C-4), 114.1 (C-2), 100.3 (C-1 0 ), 69.9, 68.8, 67.2 (2) (C-2 0 –C-5 0 ), 61.3 (C- 6 0 ), 32.4 (CH 2 CH 3 ), 25.6 (CH 3 ), 20.8, 20.5, 20.3, 20.1 (OCOCH 3 ), 6.9 (CH 2 CH 3 ). Calcd o C 19 H 27 NO 11 (Mol. W .: 445.42, Ex. Mass.: 445.16); ESI-MS (posi i e mode) m/z:468.148 [M+Na] + , 913.305 [2M+Na] + . F ac ion II: 0.10 g (19%) o an insepa able dias e eome ic mix- 310 u e o 3b as a yellowish oil; R = 0.36 (1:1 E OAc–hexane). Cha ac e iza ion o dias e eome C: 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.48 (s, 1H, NH), 5.74 (d, 1H, J 2 0 ,3 0 11.1 Hz, H-2 0 ), 5.51 (dd, 1H, J 3 0 ,4 0 3.2 Hz, J 4 0 ,5 0 1.0 Hz, H-4 0 ), 5.35 (dd, 1H, J 2 0 ,3 0 11.1 Hz, J 3 0 ,4 0 3.2 Hz, H-3 0 ), 4.43 (ddd, 1H, J 5 0 ,6 0 a 6.8, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 1.0 Hz, H-5 0 ), 4.20–4.03 (m, 2H, H-6 0 a, H-6 0 b), 2.10, 2.08, 2.01, 1.98 (4s, 12H, OCOCH 3 ), 1.88 (q, 2H, J7.3 Hz, CH 2 CH 3 ), 1.54 (s, 3H, CH 3 ), 1.00 ( , 3H, J7.3 Hz, CH 2 CH 3 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 170.4, 170.2, 169.8, 169.1 (CO), 160.2 (C-4), 114.8 (C-2), 100.9 (C-1 0 ), 69.7, 68.6, 67.7, 66.5 (C-2 0 –C-5 0 ), 61.7 (C-6 0 ), 32.4 (CH 2 CH 3 ), 320 25.8 (CH 3 ), 20.7, 20.5, 20.2, 20.1 (COCH 3 ); 6.8 (CH 2 CH 3 ). Cha ac e iza ion o dias e eome D: 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.48 (s, 1H, NH), 5.69 (d, 1H, J 2 0 ,3 0 11.1 Hz, H-2 0 ), 5.49 (dd, 1H, J 3 0 ,4 0 3.2 Hz, J 4 0 ,5 0 1.0 Hz, H-4 0 ), 5.20 (dd, 1H, J 2 0 ,3 0 11.1 Hz, J 3 0 ,4 0 3.2 Hz, H-3 0 ), 4.39 (ddd, 1H, J 5 0 ,6 0 a 6.8 Hz, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 1.0 Hz, H-5 0 ), 4.18–4.02 (m, 2H, H-6 0 a, H-6 0 b), 2.11, 2.09, 1.99, 1.97 (4s, 12H, OCOCH 3 ), 1.86 (2H, q, J7.3 Hz, CH 2 CH 3 ), 1.61 (s, 3H, CH 3 ), 1.26 ( , 3H, J7.3 Hz, CH 2 CH 3 ); 13 C NMR (CDCl 3 , 90 MHz) d(ppm): 170.4, 170.0, 169.9, 169.6 (CO), 160.2 (C-4), 113.8 (C-2), 100.9 (C-1 0 ), 69.7, 67.6, 66.2 (2) (C-2 0 –C-5 0 ), 60.3 (C-6 0 ), 33.5 (CH 2 CH 3 ), 330 24.2 (CH 3 ), 20.7, 20.6, 20.2, 20.1 (COCH 3 ); 7.9 (CH 2 CH 3 ). Calcd o C 19 H 27 NO 11 (Mol. W .: 445.42, Ex. Mass.: 445.16); ESI-MS (posi i e mode) m/z:468.147 [M+Na] + , 913.304 [2M+Na] + . F ac ion III: 0.16 g (38%) o 4 14 as a whi e solid. 3.2.2. (1 0 R)- and (1 0 S)-2 0 ,3 0 ,4 0 ,6 0 - e a-O-ace yl-1 0 ,5 0 -anhyd o- D - galac i ol-spi o-[1 0 ,5]-2,2-die hyl-4-imino-1,3-dioxolanes (2c and 3c) P epa ed om 1(0.50 g, 1.10 mmol) and pen an-3-one wi h AgOT acco ding o Gene al p ocedu e I (Sec ion 3.2). Column ch o- ma og aphy (1:1 E OAc–hexane) ga e h ee ac ions. 340 F ac ion I: 0.16 g (32%) o 2c as whi e c ys als; mp: 100–102 °C; [ a ] D +37 (c0.90, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.45 (s, 1H, NH), 5.99 (dd, 1H, J 2 0 ,3 0 11.1 Hz, J 3 0 ,4 0 3.7 Hz, H-3 0 ), 5.60 (d, 1H, J 2 0 ,3 0 11.1 Hz, H-2 0 ), 5.50 (dd, 1H, J 3 0 ,4 0 3.7 Hz, J 4 0 ,5 0 1.2 Hz, H-4 0 ), 4.85 (ddd, 1H, J 5 0 ,6 0 a 6.8 Hz, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 1.2 Hz, H-5 0 ), 4.17 (dd, 1H, J 6 0 a,6 0 b 11.6 Hz, J 5 0 ,6 0 a 6.8 Hz, H-6 0 a), 4.09 (dd, 1H, J 6 0 a,6 0 b 11.6 Hz, J 5 0 ,6 0 b 6.3 Hz, H-6 0 b), 2.17, 2.06, 2.02, 1.96 (4s, 12H, OCOCH 3 ), 1.87 (q, 2H, J7.3 Hz, CH 2 CH 3 ), 1.72 (q, 2H, J7.3 Hz, CH 2- 6A. Páhi e al. / Ca bohyd a e Resea ch xxx (2014) xxx–xxx CAR 6720 No. o Pages 11, Model 5G 15 Ap il 2014 Please ci e his a icle in p ess as: Páhi, A.; e al. Ca bohyd . Res. (2014), h p://dx.doi.o g/10.1016/j.ca es.2014.04.003 CH 3 ), 0.96 ( , 3H, J7.3 Hz, CH 2 CH 3 ), 0.88 ( , 3H, J7.3 Hz, CH 2 CH 3 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 170.1 (2), 169.6, 169.2 (CO), 350 160.4 (C-4, 3 J H-2 0 ,C-4 =6.1 Hz om HSQMBC a 125 MHz), 116.8 (C-2), 99.9 (C-1 0 ), 69.7, 68.9, 67.3 (2) (C-2 0 –C-5 0 ), 61.3 (C-6 0 ), 31.2, 29.4 (CH 2 CH 3 ), 20.5, 20.4 (2), 20.2 (COCH 3 ); 7.8, 6.7 (CH 2 CH 3 ). F ac ion II: 0.07 g (14%) o 3c as a whi e c ys als, mp: 61–63 °C; [ a ] D +59 (c1.00, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.42 (s, 1H, NH), 5.74 (d, 1H, J 2 0 ,3 0 11.1 Hz, H-2 0 ), 5.51 (dd, 1H, J 3 0 ,4 0 3.2 Hz, J 4 0 ,5 0 1.1 Hz, H-4 0 ), 5.30 (dd, 1H, J 2 0 ,3 0 11.1 Hz, J 3 0 ,4 0 3.2 Hz, H-3 0 ), 4.42 (ddd, 1H, J 5 0 ,6 0 a 6.8 Hz, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 1.1 Hz, H-5 0 ), 4.16 (dd, 1H, J 6 0 a,6 0 b 11.6 Hz, J 5 0 ,6 0 a 6.8 Hz, H-6 0 a), 4.11 (dd, 1H, J 6 0 a,6 0 b 11.6 Hz, J 5 0 ,6 0 b 6.3 Hz, H-6 0 b), 2.19, 2.03, 2.01, 1.98 (4s, 12H, 360 OCOCH 3 ), 1.88 (q, 2H, J7.3 Hz, CH 2 CH 3 ), 1.84 (q, 2H, J7.3 Hz, CH 2 CH 3 ), 0.99 ( , 3H, J7.3 Hz, CH 2 CH 3 ), 0.95 ( , 3H, J7.3 Hz, CH 2- CH 3 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 170.3 (2), 170.1, 168.6 (CO), 160.8 (C-4, 3 J H-2 0 ,C-4 =2.1 Hz om HSQMBC a 125 MHz), 116.2 (C-2), 100.8 (C-1 0 ), 69.6, 69.2, 67.7, 66.1 (C-2 0 –C-5 0 ), 61.8 (C-6 0 ), 31.6, 29.0 (CH 2 CH 3 ), 20.8, 20.5, 20.3 (2) (COCH 3 ); 8.0, 6.6 (CH 2 CH 3 ); Calcd o C 20 H 29 NO 11 (Mol. W .: 459.44, Ex. Mass.: 459.17); ESI-MS (posi i e mode) m/z:482.163 [M+Na] + , 941.337 [2M+Na] + . F ac ion III: 0.12 g (27%) o 4 14 as a whi e solid. 370 3.2.3. (1 0 R)- and (1 0 S)-2 0 ,3 0 ,4 0 ,6 0 - e a-O-ace yl-1 0 ,5 0 -anhyd o- D - galac i ol-spi o-[1 0 ,5]-4-imino-1,3-dioxolane-spi o-[2,1 00 ]- cyclopen anes (2d and 3d) P epa ed om 1(0.20 g, 0.44 mmol) and cyclopen anone wi h AgOT acco ding o Gene al p ocedu e I (Sec ion 3.2). Column ch o- ma og aphy (1:1 E OAc–hexane) ga e h ee ac ions. F ac ion I: 0.10 g (48%) o 2d as whi e c ys als; mp: 148–150 °C; [ a ] D +28 (c0.20, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.40 (s, 1H, NH), 5.98 (dd, 1H, J 2 0 ,3 0 11.1 Hz, J 3 0 ,4 0 3.6 Hz, H-3 0 ), 5.57 (d, 1H, J 2 0 ,3 0 11.1 Hz, H-2 0 ), 5.50 (dd, 1H, J 3 0 ,4 0 3.6 Hz, J 4 0 ,5 0 1.1 Hz, H-4 0 ), 380 4.85 (ddd, 1H, J 5 0 ,6 0 a 6.8 Hz, J 5 0 6 0 b 6.3 Hz, J 4 0 ,5 0 1.1 Hz, H-5 0 ), 4.15 (dd, 1H, J 6 0 a,6 0 b 11.6 Hz, J 5 0 ,6 0 a 6.8 Hz, H-6 0 a) 4.09 (dd, 1H, J 6 0 a,6 0 b 11.6 Hz, J 5 0 ,6 0 b 6.3 Hz, H-6 0 b), 2.16, 2.05, 2.03, 1.97 (4s, 12H, OCOCH 3 ), 1.92–1.84 (m, 4H, 2CH 2 ), 1.82–1.68 (m, 4H, 2CH 2 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm): 170.0 (2), 169.6, 169.0 (CO), 158.8 (C-4, 3 J H-2 0 ,C-4 =6.1 Hz), 116.2 (C-2), 100.1 (C-1 0 ), 69.9, 68.6, 67.3, 67.2 (C-2 0 –C-5 0 ), 61.2 (C-6 0 ), 38.2, 36.6, 23.6, 22.6 (4CH 2 ), 20.6, 20.5 (2), 20.4 (COCH 3 ); Calcd o C 20 H 27 NO 11 (Mol. W .: 457.43, Ex. Mass.: 457.16); ESI-MS (posi i e mode) m/z:480.149 [M+Na] + , 937.306 [2M+Na] + . 390 F ac ion II: T aces o 3d insu ficien o NMR cha ac e iza ion. Calcd o C 20 H 27 NO 11 (Mol. W .: 457.43, Ex. Mass.: 457.16); ESI- MS (posi i e mode) m/z:480.147 [M+Na] + , 937.306 [2M+Na] + . F ac ion III: 0.045 g (26%) o 4 14 as a whi e solid. 3.2.4. (1 0 R)- and (1 0 S)-2 0 ,3 0 ,4 0 ,6 0 - e a-O-ace yl-1 0 ,5 0 -anhyd o- D - galac i ol-spi o-[1 0 ,5]-4-imino-1,3-dioxolane-spi o-[2,1]- cyclohexanes (2e and 3e) P epa ed om 1(0.50 g, 1.10 mmol) and cyclohexane wi h AgOT acco ding o Gene al p ocedu e I (Sec ion 3.2). Column ch o- ma og aphy (1:1 E OAc–hexane) ga e h ee ac ions. 400 F ac ion I: 0.23 g (44%) o 2e as whi e c ys als; mp: 124–126 °C; [ a ] D +14 (c0.22, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.40 (s, 1H, NH), 6.01 (dd, 1H, J 2 0 ,3 0 10.5 Hz, J 3 0 ,4 0 3.2 Hz, H-3 0 ), 5.57 (d, 1H, J 2 0 ,3 0 10.5 Hz, H-2 0 ), 5.51 (dd, 1H, J 3 0 ,4 0 3.2 Hz, J 4 0 ,5 0 1.0 Hz, H-4 0 ), 4.85 (ddd, 1H, J 5 0 ,6 0 a 7.3 Hz, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 1.0 Hz, H-5 0 ), 4.10–4.08 (m, 2H, H-6 0 a, H-6 0 b), 2.18, 2.08, 2.04, 1.97 (4s, 12H, OCOCH 3 ), 1.87–1.81 (m, 2H, CH 2 ), 1.77–1.56 (m, 4H, 2CH 2 ), 1.53–1.33 (m, 2H, CH 2 ), 1.30–1.23 (m, 2H, CH 2 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 170.8 (2), 169.2, 169.8 (CO), 158.2 (C-4, 3 J H-2 0 ,C- 4 =5.3 Hz), 113.2 (C-2), 100.1 (C-1 0 ), 69.9, 68.9, 67.5 (2) (C-2 0 –C- 410 5 0 ), 61.3 (C-6 0 ), 37.2, 36.4, 24.4, 23.1 (2) (5CH 2 ), 20.8, 20.6 (2), 20.3 (COCH 3 ); Calcd o C 21 H 29 NO 11 (Mol. W .: 471.46, Ex. Mass.: 471.17); ESI-MS (posi i e mode) m/z:494.164 [M+Na] + , 965.339 [2M+Na] + . F ac ion II: 0.04 g (8%) o 3e as whi e c ys als; mp: 112–114 °C; [ a ] D +23 (c0.20, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 7.40 (s, 1H, NH), 5.75 (d, 1H, J 2 0 ,3 0 10.5 Hz, H-2 0 ), 5.50 (dd, 1H, J 3 0 ,4 0 3.2 Hz, J 4 0 ,5 0 1.0 Hz, H-4 0 ), 5.26 (dd, 1H, J 2 0 ,3 0 10.5 Hz, J 3 0 ,4 0 3.2 Hz, H-3 0 ), 4.41 (ddd, 1H, J 5 0 ,6 0 a 7.3 Hz, J 5 0 ,6 0 b 6.3 Hz, J 4 0 ,5 0 1.0 Hz, H-5 0 ), 4.16 (dd, 1H, J 6 0 a,6 0 b 11.6 Hz, J 5 0 ,6 0 a 7.3 Hz, H-6 0 a), 4.07 (dd, 1H, J 6 0 a,6 0 b 420 11.6 Hz, J 5 0 ,6 0 b 6.3 Hz, H-6 0 b), 2.20, 2.06, 2.01, 1.95 (4s, 12H, OCOCH 3 ), 1.88–1.81 (m, 2H, CH 2 ), 1.79–1.60 (m, 6H, 3CH 2 ), 1.52–1.41 (m, 2H, CH 2 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 170.3 (2), 168.9, 168.8 (CO), 160.3 (C-4), 113.1 (C-2), 100.8 (C-1 0 ), 69.7, 69.3, 67.7, 66.0 (C-2 0 –C-5 0 ), 61.8 (C-6 0 ), 37.0, 36.0, 24.3, 23.3 (2) (5CH 2 ), 20.6 (2), 20.5 (2) (COCH 3 ); Calcd o C 21 H 29 NO 11 (Mol. W .: 471.46, Ex. Mass.: 471.17); ESI-MS (posi i e mode) m/z: 494.164 [M+Na] + , 965.336 [2M+Na] + . F ac ion III: 0.11 g (25%) o 4 14 as a whi e solid. 3.2.5. (1 0 R)-2 0 ,3 0 ,4 0 ,6 0 -Te a-O-benzoyl-1 0 ,5 0 -anhyd o- D -gluci ol- 430 spi o-[1 0 ,5]-2,2-dime hyl-4-imino-1,3-dioxolane (6a) P epa ed om 5(0.50 g, 0.71 mmol) and ace one wi h AgOT acco ding o Gene al p ocedu e I (Sec ion 3.2). Column ch oma og- aphy (1:2 E OAc–hexane han E OAc) ga e wo ac ions. F ac ion I: 0.18 g (37%) o 6a as a colou less oil; R = 0.51 (1:2 E OAc–hexane); [ a ] D +63 (c0.52, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 8.04–7.24 (m, 20H, A H), 7.73 (s, 1H, NH), 6.80 (pseudo , 1H, J 2 0 ,3 0 10.2 Hz, J 3 0 ,4 0 9.7 Hz, H-3 0 ), 5.85 (d, 1H, J 2 0 ,3 0 10.2 Hz, H-2 0 ), 5.76 (pseudo , 1H, J 4 0 ,5 0 9.9 Hz, J 3 0 ,4 0 9.7 Hz, H-4 0 ), 5.13 (ddd, 1H, J 4 0 ,5 0 9.9 Hz, J 5 0 ,6 0 b 4.5 Hz, J 5 0 ,6 0 a 1.2 Hz, H-5 0 ), 440 4.63 (dd, 1H, J 6 0 a,6 0 b 12.0 Hz, J 5 0 ,6 0 a 1.2 Hz, H-6 0 a), 4.47 (dd, 1H, J 6 0 a,6 0 b 12.0 Hz, J 5 0 ,6 0 b 4.5 Hz, H-6 0 b), 1.61, 1.29 (2s, 6H, CH 3 ); 13 CNMR (CDCl 3 , 90 MHz): d(ppm) 166.0, 165.4, 165.3, 164.8 (CO), 160.5 (C-4, 3 J H-2 0 ,C-4 =5.4 Hz, om HSQMBC a 125 MHz), 112.8 (C-2), 100.3 (C-1 0 ), 70.8, 70.7, 70.5, 69.4 (C-2 0 –C-5 0 ), 63.1 (C-6 0 ), 27.6, 26.7 (CH 3 ); Calcd o C 38 H 33 NO 11 (Mol. W .: 679.67, Ex. Mass.: 679.21); ESI-MS (posi i e mode) m/z:702.190 [M+Na] + , 1381.399 [2M+Na] + . F ac ion II: 0.21 g (46%) o 7 32 as a whi e solid. 3.2.6. (1 0 R)-2 0 ,3 0 ,4 0 ,6 0 -Te a-O-benzoyl-1 0 ,5 0 -anhyd o- D -gluci ol- 450 spi o-[1 0 ,5]-2,2-die hyl-4-imino-1,3-dioxolane (6c) P epa ed om 5(0.50 g, 0.71 mmol) and pen an-3-one wi h AgOT acco ding o Gene al p ocedu e I (Sec ion 3.2). Column ch o- ma og aphy (1:2 E OAc–hexane han E OAc) ga e wo ac ions. F ac ion I: 0.23 g (46%) o 6c as a whi e oam; R = 0.49 (1:2 E OAc–hexane); [ a ] D +60 (c0.40, CHCl 3 ); 1 H NMR (CDCl 3 , 360 MHz): d(ppm) 8.05–7.20 (m, 20H, A H), 7.71 (s, 1H, NH), 6.82 (pseudo , 1H, J 2 0 ,3 0 10.2 Hz, J 3 0 ,4 0 9.8 Hz, H-3 0 ), 5.92 (d, 1H, J 2 0 ,3 0 10.2 Hz, H-2 0 ), 5.76 (pseudo , 1H, J 3 0 ,4 0 9.8 Hz, J 4 0 ,5 0 9.7 Hz, H-4 0 ), 5.13 (ddd, 1H, J 4 0 ,5 0 9.7 Hz, J 5 0 ,6 0 b 5.6 Hz, J 5 0 ,6 0 a 2.2 Hz, H-5 0 ), 460 4.64 (dd, 1H, J 6 0 a,6 0 b 12.0 Hz, J 5 0 ,6 0 a 2.2 Hz, H-6 0 a), 4.50 (dd, 1H, J 6 0 a,6 0 b 12.0 Hz, J 5 0 ,6 0 b 5.6 Hz, H-6 0 b), 1.87 (q, 2H, J7.2 Hz, CH 2 CH 3 ), 1.57 (q, 2H, J7.4 Hz, CH 2 CH 3 ), 0.90 ( , 3H, J7.4 Hz, CH 2 CH 3 ), 0.63 ( , 3H, J 7.4 Hz, CH 2 CH 3 ); 13 C NMR (CDCl 3 , 90 MHz): d(ppm) 165.9, 165.4 (2), 164.8 (CO), 160.6 (C-4, 3 J H-2 0 ,C-4 =4.9 Hz), 116.6 (C-2), 99.9 (C-1 0 ), 70.9, 70.7, 70.5, 69.5 (C-2 0 –C-5 0 ), 63.0 (C-6 0 ), 31.2, 29.1 (CH 2- CH 3 ), 7.8, 6.6 (CH 2 CH 3 ); Calcd o C 40 H 37 NO 11 (Mol. W .: 707.72, Ex. Mass.: 707.24); ESI-MS (posi i e mode) m/z:730.223 [M+Na] + , 1437.468 [2M+Na] + . F ac ion II: 0.16 g (35%) o 7 32 as a whi e solid. 470 3.2.7. (1 0 R)-2 0 ,3 0 ,4 0 ,6 0 -Te a-O-benzoyl-1 0 ,5 0 -anhyd o- D -gluci ol- spi o-[1 0 ,5]-4-imino-1,3-dioxolane-spi o-[2,1 00 ]-cyclopen ane (6d) P epa ed om 5(0.50 g, 0.71 mmol) and cyclopen anone wi h Ag 2 CO 3 acco ding o Gene al p ocedu e I (Sec ion 3.2). Column A. Páhi e al. / Ca bohyd a e Resea ch xxx (2014) xxx–xxx 7 CAR 6720 No. o Pages 11, Model 5G 15 Ap il 2014 Please ci e his a icle in p ess as: Páhi, A.; e al. Ca bohyd . Res. (2014), h p://dx.doi.o g/10.1016/j.ca es.2014.04.003