X-Ray Structure of 8alpha-Acetoxy-1,3,4,10-Tetrahydro-1alpha,10alpha-Epoxyachillin

GEORGE A. SIM 1413 In e na ional Tables o X- ay C ys allog aphy (1974). Vol. IV. Bi mingham: Kynoch P ess. (P esen dis ibu o D. Reidel, Do d ech .) JOI-INSON, C. K. (1965). ORTEP. Repo ORNL-3794. Oak Ridge Na ional Labo a o y, Tennessee. MALL ~SON, P. R. & MUIR, K. W. (1985). J. Appl. C ys . 18, 51-53. SC,MID, E. D. & BROSA, B. (1972). J. Chem. Phys. 56, 6267-6268. SUTHERLAND, H. H. (1969). Ac a C ys . B25, 171-178. SUTHERLAND, H. H. & Ho , T. G. (1968). Ae a C ys . B24, 1207-1213. SUTHERLAND, H. H. & HOY, T. G. (1969). Ac a C ys . B25, 2385-239 I. TROY ER, J. (1961). Ac a C ys . 14, 1135-1140. YouNo, D. W., TOLLIN, P. & SUTHERLAh~, H. H. (1968). Ac a C ys . B24, 161-167. Ac a C ys . (1986). C42, 1413-1415 X- ay S uc u e o 8¢x-Aee oxy- 1,3,4,10- e ahyd o- I a,l 0¢x-epoxyaehillin BY M. D. ESTRADA, A. CONDE AND R. M.ARQUEZ Depa amen o de Fisica del Es ado S6lido, Facul ad de F sica, Uni e sidad de Se illa, Spain ANI) R. JI~kNEz GARAY Depa amen o de F[sica, Facul ad de Ciencias, Uni e sidad de C6diz, Spain (Recei ed 3 Janua y 1986; accep ed 16 Ap il 1986) Abs ac . (5aI-I,6/~-I, 11 aH)-8a-Ace oxy- 1,5-dihyd o-2- oxo-lc ,10c -epoxyguaian-6,12-olide, C~7H2206, M = 322.3, o ho hombic P2~212~, a= 14.964(6), b= 17.057(4), c=6.218(4)A, V=1587(1)A 3, Z=4, D,n=l.349(5), D x=l.349Mgm -3, 2(MoKa)= 0.7107 A, # = 0.09 mm -l, F(000) = 688, oom em- pe a u e, inal wR--0.068 o 1899 obse ed e lex- ions. The con o ma ions displayed by he cyclo- pen anone, y-lac one and cyclohep ane ings a e nea o a wis , an en elope and a chai o m, espec i ely. The cyclopen anone-cyclohep ane and y-lac one-eyclo- hep ane ing usions a e cis and ans, espec i ely. Packing in he c ys al is due o weak C-H...O hyd ogen-bond in e ac ions gi ing chains o molecules pa allel o [010] and [001]. In oduc ion. The i le compound (I) (m.p. 469-471 K, M ÷ m/z 322) was p epa ed, along wi h i s s e eoisome a C(1) and C(10) (II), om 8a-hyd oxyachillin (III), a na u al p oduc isola ed om A emisia lana a Willd (Gonz~ilez, Be mejo, de la Rosa & Massane , 1976). (I) (II) (III) The de ailed 1H NMR analysis and he c i e ia based on he H(6) pa amagne ic shi (Ba es, P och/lzka & Cekan, 1963; Ando, Akahane & Takase, 1978), usually 0108-2701/86/101413-03501.50 employed o es ablish he s e ecchemis y o he 1,10-epoxyguaianolides (Bhacca & Williams, 1964), seem o ail in his case (Massane , 1986). An X- ay di ac ion analysis was sugges ed o es ablish de ini ely he con o ma ional de ails o (I). Expe imen al. Single c ys als in he o m o colou less needles elonga ed along [001], p epa ed in he O ganic Chemis y Depa men o he Uni e si y o C/~diz. Dm by lo a ion. C ys al 0.12 × 0-10 × 0.16 mm. Uni -cell pa ame e s om 25 e lexions, 5 < 0 < 15 °. En a - Nonius CAD-4 di ac ome e , g aphi e mono- ch oma o , 2<0<30 ° (0<h<21, 0<k<24, 0 < l < 8), ~-20 scan mode. Two s anda d e lexions (F;10, 4i0), a ia ion in in ensi y < 3% o mean alue. 2638 independen e lexions measu ed, 739 conside ed unobse ed [I<2c (/)]. Lo en z and pola iza ion co ec ion, no co ec ion o abso p ion o ex inc ion. S uc u e sol ed by di ec me hods using MULTAN80 (Main, Fiske, Hull, Lessinge , Ge main, Decle cq & Wool son, 1980). The chi ali y was assumed on he basis o chemical in o ma ion. Full-ma ix leas -squa es e inemen ; Yw( IF o I - IF c I )2 minimized wi h weigh - ing scheme based on s a is ical-coun c i e ion (w = 1~o 2). Di e ence Fou ie syn hesis e ealed he 22 H-a om posi ions; iso opic empe a u e ac o B = 4.0 A 2 o H a oms; u he leas -squa es e inemen including posi ional pa ame e s o H a oms. A inal con e gence A/c < 0.4, R = 0.081, wR = 0.068, S = 2.7 o 274 e ined a iables; numbe o e lexions/ numbe o pa ame e s = 7.87. Final accu acy o he e inemen is limi ed by he poo quali y o he c ys als. © 1986 In e na ional Union o C ys allog aphy 1414 8 c -AC ETOXY- 1,3,4,10-TETRAHYDRO- 1 ~, 10a-EPOXYACHILLIN Table 1. A omic coo dina es and equi alen iso opic he malpa ame e s (A 2 x 10 a) q~ :~ c~, C9 ~CB / Ueq = .} T..iZjUua'~ aT a aj(cosa ,a.l). °s~ 13 x y z Ueq oz 0(1) 0.6743 (2) 0.0376 (2) O. 1305 (5) 35 (1) 0(2) 0.6950 (2) -0.0913 (2) 0.1379 (5) 46 (1) 0(3) 0.6375 (2) 0.3552 (2) 0.3343 (6) 56 (1) 0(4) 0.4871 (2) 0.2727 (1) 0.1455 (4) 34 (1) 0(5) 0.4031 (2) 0.0290 (2) 0.4900 (4) 30 (1) cxo~ ~~ 0(6) 0.3865 (2) 0.0793 (2) 0.8204 (5) 59 (1) C(1) 0.4711 (2) 0.0870 (2) 0.4425 (6) 25 (1) ~ ~ex6 C(2) 0.5320 (2) 0.0475 (2) 0.2818 (6) 26 (1) c11 l ~c12 ~ c12 C(3) 0.6172 (2) 0.0947 (2) 0.2371 (6) 24 (1) ~¢" C(4) 0.6056 (3) 0.1653 (2) 0.0901 (6) 28 (1) ~o3 04 ~ ez7 C(5) 0.5672 (2) 0.2341 (2) 0.2199 (7) 28 (1) C(6) 0.4838 (3) 0.2317 (2) 0.3492 (7) 31 (1) C(7) 0.4254 (2) 0.1590 (2) 0.3445 (7) 33 (1) C(8) 0.5709 (3) -0.0325 (2) 0.3418 (8) 35 (1) Fig. 1. A iew o he molecule in he xy p ojec ion. C(9) 0.6522 (3) -0.0362 (3) 0.1950 (7) 36 (1) C(10) 0.6976 (3) 0.1966 (2) 0.0101 (7) 32 (I) C(11) 0.7289 (3) 0.2493 (2) 0.1941 (8) 39 (1) C(12) 0.6444 (3) 0.2892 (2) 0.2657 (6) 36 (1) C(13) 0.3667 (2) 0.0309 (2) 0.6902 (7) 34 (1) C(14) 0.2993 (3) -0.0319 (3) 0.7188 (8) 52 (2) C(15) 0.5988 (3) -0.0430 (3) 0.5785 (7) 48 (2) o6 C(16)C(17) 0.4701(3)0"6861 (3) 0.2429 (3) -0.1984 (7) 46 (2) Je 5 ,,~ / 02 ~,~ 3,1 " 1o~3(c2~c~ ~o33 c,~ '" o, c,, ~ 03 0.2835 (3) 0.5445 (7) 40 (1) Fig. 2. Bond dis ances (A) and angles (o) in he molecule. Values o angles C(6)-C(5)-C(12), C(5)-C(6)-C(17), O(4)-C(5)-C(4) and O(4)-C(6)-C(7) a e 123.8 (3), 122.1 (3), 119.4 (3) and 113.4 (3) ° , espec i ely. S anda d de ia ions a e in he anges 0.004-0.007 ~, o dis ances and 0.3-0.4 ° o angles. Max. and min. alues in inal di e ence densi y map 0.3 and -0.25 e A -a, espec i ely. A omic sca e ing ac o s om In e na ional Tables o X- ay C ys al- log aphy (1974). Calcula ions ca ied ou on a Uni ac 1100 compu e . C ys allog aphic p og ams o XRAY70 sys em (S ewa , Kundell & Baldwin, 1970) used h oughou . Discussion. F ac ional a omic coo dina es and equi a- len iso opic empe a u e ac o s (Hamil on, 1959) o non-H a oms a e lis ed in Table 1.* The molecula con o ma ion and a om labelling a e shown in Fig. 1. Bond leng hs and angles o non-H a oms a e indica ed in Fig. 2. C-H dis ances ange om 0.88 (5) o 1.13 (5) A [mean alue 1.01 (5) A]. Molecula geome y The Newman p ojec ions o Fig. 3 show how he h ee ings a e used along he C(3)-C(2) and C(4)-C(5) bonds. The s e eochemis y o he molecule (Fig. 1) is as ollows: C(4)- ll-I is cis o C(15)- lO(4); C(2)- lH is ans o C(3)-aH; C(4)-#H is cis o C(10)- lCH3 and o C(5)-C(6); C(2)- ll-I is cis o he C(1) ace oxy g oup. Thus he cyclopen anone-cyclo- hep ane and he y-lac one-cyclohep ane ing junc ions a e cis and ans, espec i ely. * Lis s o s uc u e ac o s, aniso opic he mal pa ame e s and H-a om pa ame e s ha e been deposi ed wi h he B i ish Lib a y Lending Di ision as Supplemen a y Publica ion No. SUP 43028 (14 pp.). Copies may be ob ained h ough The Execu i e Sec e a y, In e na ional Union o C ys allog aphy, 5 Abbey Squa e, Ches e CH1 2HU, England. 0(I) H(4) H(2) C(6) //OU.) -73~3) / / ~ -2 ~j H¢3) ~ COuJ C(1) COD Fig. 3. Newman p ojec ions illus a ing he coupling o he h ee used ings in he molecule. To sion angles a e in o M. D. ESTRADA, A. CONDE, R. M,~RQUEZ AND R. JIMI~NEZ GARAY 1415 The con o ma ion o he cyclopen anone ing as indica ed by he endocyclic o sion angles is a wis o m. In e ms o pucke ing coo dina es (C eme & Pople, 1975) he ampli ude and phase alues a e q = 0.381 (4) A and ¢ = 82.76 (6) ° o he sequence C(5)-C(4)-C(10)-C(11)-C(12). The asymme y pa ame e (Na delli, 1983a) AC2[C(5)] =0.026 (2) shows an app oxima e wo old symme y in he ing. Fo he y-lac one ing he esul ing con o ma ion is an en elope o m. In e ms o pucke ing coo dina es (C eme & Pople, 1975) he ampli ude and phase alues a e q = 0.385 (4)A and ~0= 67.1 (5) ° o he sequence O(1)-C (3)-C (2)-C (8)-C (9) and he asym- me y pa ame e ACs[C(2)] = 0.029 (2) indica es an app oxima e mi o -plane symme y in he ing. The cyclohep ane ing displays an app oxima e chai con o ma ion wi h a mi o pseudo-symme y om C(2) o he midpoin o he C(5)-C(6) bond {ACs[C(2)] = 0.024 (2)}. Values o he o sion angles C(4)-C(5)-C(6)-C(7) = -5.1 (6), C(5)-C(6)- C(7)-C(1) = 65.5 (5), C(2)-C(1)-C(7)-C(6) = -82.5 (4) and C(7)-C(1)-C(2)-C(3)= 72.2 (4) ° a e in ag eemen wi h hose (0, 66, 84, 64 °) p oposed by Hend ickson (1967) o a cyclohep ane molecule wi h equal bond leng hs in a pe ec chai con o ma ion. Fo he ideal cyclohep ane molecule he a e age bond angle is 116 o and alues ange om 114 o 118 o. In his case he mean alue is 115.3 (3) ° bu a la ge dispe sion, om 109 o 125 ° , is obse ed. In e ms o pucke ing coo dina es he ampli ude and phase alues a e q2=0.340(4), q3=0.710(4)A and P2=71.8(7), ~03 =--156.7 (4) ° [Q = 0.787 (4)A, and 02= 25.6 (3) °] o he sequence C(1)-C(2)-C(3)-C(4)- C(5)-C(6)-C(7). The epoxide b idge be ween C(5) and C(6) p oduces a high s ain a ound he C(5)-C(6) bond. The e a e some ea u es suppo ing his idea: he sho C(5)-C(6) dis ance o 1.485 (6)A, he endency o ha e a pla- na dis ibu ion o he bonds a ound C(5) and C(6) as e ealed by he o sion angles C(4)-C(5)- C(6)-C(7) = -5.1 (6), C(12)-C(5)-C(6)-C(7) = -158.8 (4) and C(17)-C(6)-C(5)-C(4) = 151.9 (4) ° and he dihed al angle be ween he leas -squa es planes h ough he C(4)-C(5)-C(6)-C(7) g oup and he epoxide b idge o 76.6 (1) °. This is he usual geome i- cal de o ma ion ound a ound he epoxide b idge (Foces-Foces, Cano & Ga cia-Blanco, 1977). C ys al packing In he c ys al cohesion, some in e molecula in e - ac ions may be conside ed as hyd ogen bonds: C(8)- n(8)...O(4)(-x+ 1, y-½, -z+9 and C(17)- H(172)...O(2)(-x+ 1, y+½, -z+9, linking molecules ela ed by a sc ew axis pa allel o [010], and C(10)- H(10)...O(2)(-x+~, -y, z-9, linking molecules ela ed by a sc ew axis pa allel o [001]. De ails o he geome y o hese con ac s a e: C(8)-H(8)= 0.99 (4), C(8)...O(4) = 3.435 (5), H(8)...O(4) = 2.61 (4) A, C(8)-H(8)...O(4) = 140 (3)°; C(17)-H(172) = 1.09 (5), C(17)...O(2)-- 3.458 (5), H(172)...O(2)= 2.54 (5)/~, C(17)-H(172)...O(2) = 141 (4)°; C(10)-H(10) = 1-09 (5), C(10)...O(2) = 3.341 (5), H(10)...O(2) = 2.59 (5) ]k, C(I0)-H(I0)...O(2) = 125 (3) °. As obse ed, he H...O dis ances o hese con ac s a e close o he sum o he an de Waals adii o H and O (1.20 and 1.50 A) and he C-H...O angles ha e alues lowe han he mean alue (152.7 ° ) epo ed o in e molecula C-H...O hyd ogen bonds wi h H...O=2.40A (Taylo & Kenna d, 1982). The e o e, alues ound o he C-H...O angles a e app eciably highe han he gene ally accep ed low limi o 90 ° o he dono -p o on...accep o angle in a hyd ogen bond and so hey should be conside ed as weak hyd ogen bonds. No o he con ac s signi ican ly sho e han he sum o he an de Waals adii ha e been de ec ed. The molecula geome y and c ys al packing we e compu ed by PARST (Na delli, 1983b). The au ho s hank P o esso G. Ma inez Massane and D Macias Dominguez (Uni e si y o C~ diz) o supplying he c ys als and o help ul discussions on chemical aspec s and P o esso A. L6pez-Cas o o collec ing he di ac ome e da a. Re e ences ANDO, M., AKAHANE, A. & TAKASE, K. (1978). Chem. Le . pp. 727-730. BATES, R. B., PROCH.2~ZKA, V. (~; CEKAN, Z. (1963). Te ahed on Le . pp. 887-890. BHACCA, N. S. & WILLIAMS, D. H. (1964). In Applica ions o NMR Spec oscopy in O ganic Chemis y. San F ancisco: Holden- Day. CREMER, D. & POPLE, J. A. (1975). J. Am. Chem. Soc. 97, 1354-I358. FOCES-FOCES, C., CANO, F. H. & GARCiA-BLANCO, S. (1977). Ac a C ys . B33, 3521-3524. GONZALEZ, A. G., BERMEJO, J., DE LA ROSA, A. D. • MASSANET, G. M. (1976). An. Qu[m. 72, 695-697. HAMILTON, W. C. (1959). Ac a C ys . 12, 609-610. HENDRICKSON, J. B. (1967). J. Am. Chem. Soc. 89, 7036-7043. In e na ional Tables o X- ay C ys allog aphy (1974). Vol. IV. Bi mingham: Kynoch P ess. (P esen dis ibu o D. Reidel, Do d ech .) MAIN, P., FISKE, S. J., HULL, S. E., LESSINGER, L., GERMAIN, G., DECLERCQ, J.-P. & WOOLFSON, M. M. (1980). MULTAN80. A Sys em o Compu e P og ams o he Au oma ic Solu ion o C ys al S uc u es om X- ay Di ac ion Da a. Uni s. o Yo k, England, and Lou ain, Belgium. MASSANET, G. M. (1986). To be published. NARDELLI, M. (1983a). Ac a C ys . C39, 1141-1142. NARDELLI, M. (1983b). Compu . Chem. 7, 95-98. STEWART, J. M., KUNDELL, F. A. & BALDWIN, J. C. (1970). The XRA Y70 sys em. Compu e Science Cen e , Uni . o Ma yland, College Pa k, Ma yland. TAYLOR, R. & KE~NARD, O. (1982). J. Am. Chem. Soc. 104, 5063-5070.