N-acetyl-2,3,4,6-tetra-O-acetyl-N-benzyl-β-D-glucopyranosylamine

378 C26HI8C12N2S2 References Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S I-S 19. Bocelli, G. & Cantoni, A. (1992). Acta Cryst. C48, 961-963. Burla, M. C., Camalli, M., Cascarano, G., Giacovazzo, C., Polidori, G., Spagna, R. & Viterbo, D. (1989). J. Appl. Cryst. 22, 389. Casella, L. (1984). Inorg. Chem. 23, 2781-2787. Castro, J., Romero, J., Vfizquez, J. A. G., Durfin, M. L., Castineiras, A. & Sousa, A. (1990). J. Chem. Soc. Dalton Trans. pp. 3255-3258. Charles, R. G. & Freiser, H. (1953). J. Org. Chem. 18, 422-425. Enraf-Nonius (1988). CAD-4 VAX/PC Fortran System. Operator's Guide to the Enraf-Nonius CAD-4 Diffractometer Hardware, its Software and the Operating System. Enraf-Nonius, Delft, The Netherlands. Enraf-Nonius (1993). CAD-4 Express Software. Version 1.1. Enraf-- Nonius, Delft, The Netherlands. Fair, C. K. (1990). MolEN. An Interactive Intelligent System for Crystal Structure Analysis. Enraf-Nonius, Delft, The Netherlands. Hordvik, A. (1966). Acta Chem. Scand. 20, 1885-1891. Ide, S., 0zta~, S. G., Ancm, N. & Ttiziin, M. (1996). Cryst. Res. Technol. 31, 427-431. Jadamus, H., Fernando, Q. & Freiser, H. (1964). J. Am. Chem. Soc. 86, 3056-3059. Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA. Krasinski, R. A. & Fackler, J. P. Jr (1994). Acta Cryst. C50, 2039- 2041. Lee, J. D. (1972). Naturwissenchaften, 15, 36. Lee, J. D. & Bryant, M. W. R. (1970). Acta Cryst. B26, 1729-1735. Marsden, C. J. & Smith, B. J. (1988). J. Phys. Chem. 92, 347-353. Meyer, B. (1976). Adv. Inorg. Chem. Radiochem. 18, 287-317. Muller, A. & Diemann, E. (1987). Adv. Inorg. Chem. 31, 89-122. Orpen, A. G., Brammer, L., Allen, F. H., Kennard, O., Watson, D. G. & Taylor, R. (1989). J. Chem. Soc. Dalton Trans. pp. SI-$83. Sugiura, Y. & Hirayama, Y. (1976). lnorg. Chem. 15, 679-681. Sugiura, Y., Hirayama, Y., Tanaka, H. & Ishizu, K. (1975). J. Am. Chem. Soc. 97, 5577-5581. Tinant, B. & Declercq, J.-P. (1986). Acta Cryst. C42, 383-384. Acta Cryst. (1997). C53, 378-379 Comment Many natural products and their derivatives have an N-acyl group joined to a sugar moiety and as the chemical and biological properties of these compounds depend on their structure and conformation, the correct determination is important. In some N-alkyl-N-glycosyl- amides, the presence of two conformational isomers is observed in solution due to hindered rotation about the amide C--N bond. In the present case, (I), no preferred conformation was established in solution so we undertook a crystal structure determination. CH2OAc CH'~C~He AcO"X'-L ~° I " " ~ AcO~ N--.ff~CH3 OAc O (I) Crystals of (I) were obtained (Avalos, Babiano, Durfin, Jim6nez & Palacios, 1992) from the reaction of acetic anhydride with N-benzylglucopyranosylamine in pyridine. The same authors studied several sugar amides and thioamides, including the title compound, by NMR spectroscopy. Our structural analysis shows that only one anomer, i.e. /3-D-glucopyranose, and one rotamer along the N--C bond (E) are present in the crystal. A PLATON view (Spek, 1994) of the title molecule viewed along the z axis, together with the atomic numbering, is shown in Fig. 1. Bond lengths and angles agree with those of analogous compounds (Banic, Kojic-Prodic, Kroon-Beterburg & Keglevic, 1994; Vega, L6pez-Castro & Mfirquez, 1986), although the pyranose endocyclic bond lengths [O1--C2 1.435 (3) and O--C5 1.427 (3)A] do not show the anomeric effect characteristic of this ring. The phenyl, acetoxy and acetamide groups are essentially planar. lV-A cetyl-2,3,4,6-tetra.O-acetyl.N.benzyl. /~-D-glucopyranosylamine MARIA JESOS DL~WZ, MARIA DOLORES ESTRADA, AMPARO L6PEZ-CASTRO AND SIME6N P~REZ-GARRIDO Instituto de Ciencias de Materiales de Sevilla, and Departamento de Ffsica de la Materia Condensada, CSIC-Universidad de Sevilla, Apartado 1065, 41080 Sevilla, Spain. E-mail: [email protected] (Received 16 May 1996; accepted 21 October 1996) Abstract The solid-state conformation of the title compound, C23H29NOIo, has been unequivocally established. The configuration at C 1 is/3-D-glucopyranose and the pyranose ring is essentially a perfect chair. Only the E rotamer along the N---C bond is observed. @ 1997 International Union of Crystallography Printed in Great Britain - all rights reserved C62 06~C61 C16(~ ~ 17 ~2 ~O6 C15~ ?C18 C42~4~ ~C~ 6 ~C14 ~C19 Fig. 1. A PLATON (Spek, 1994) plot of the title compound showing 30% probability displacement ellipsoids and the atom-numbering scheme. H atoms have been omitted for clarity. Acta Cr3'stallographica Section C ISSN 0108-2701 © 1997 MARL4. JESUS DlfidqEZ et al. 379 The geometry observed for the pyranose ring shows no significant distortion from a perfect chair. The 04 and 02 ring substituents are on one side, at distances of 0.541 (2) and 0.371 (2)]k, respectively, and C6 and 03 are on the other side, at distances of -0.171 (3) and -0.584 (2) ,~, respectively, of the best plane defined by atoms O, C1, C2, C3, C4 and C5, while the N1 atom is .practically in this plane at a distance of -0.012(2)A. In terms of ring-puckering coordinates (Cremer & Pople, 1975), amplitudes and phase magnitudes are Q = 0.577 (2)A, qo = -150(2) and 0 = 172 (3) °. The asymmetry parameters (Nardelli, 1983) are ACs(O1) = 0.028(1) and AC2(C2--O1) = 0.004 (1). Crystal packing is governed only by van der Waals interactions. Experimental Crystals of (I) were obtained (Avalos, Babiano, DurS.n, Jim6nez & Palacios, 1992) from a reaction in which acetic anhydride was gradually added to a solution of N-benzylgluco- pyranosylamine in pyridine at 273 K. Table 1. Selected geometric parameters (A, o) O2--C2 1.440 (3) N1--421 1.441 (3) O3--C3 1.442 (3) NI---CI3 1.476 (4) O4---C4 1.438 (3) C5----C6 1.509 (4) O 12-----C 11 1.210 (4) CI 1-----C 12 i.497 (5) NI---C11 1.381 (4) CI I--N l-----Cl 120.5 (2) O12--C11--C12 120.5 (3) C 11--N I-----CI 3 117.9(2) NI--CI 1--C12 119.2(3) C I--N 1-----~ 13 120.0(2) N l-----C 13-----C 14 113.1 (2) O12----C 11--NI 120.3 (3) H atoms were placed in geometrically calculated positions, with C--H = 1.00 A, and included as fixed contributors in the structure-factor calculations, with isotropic displacement parameters related to those of the parent atom. The absolute configuration was not determinable from the diffraction data and was taken to be that of the starting material. Data collection: CAD-4 Software (Enraf-Nonius, 1989). Cell refinement: SET4 (de Boer & Duisenberg, 1984) and CELDIM (Rettig, 1989). Data reduction: XRAY'/6 (Stewart et al., 1980). Program(s) used to solve structure: SIR92 (Altomare et al., 1994). Program(s) used to refine structure: SHELXL93 (Sheldrick, 1993). Molecular graphics: PLATON (Spek, 1994). Software used to prepare material for publication: SHELXL93 and PARS'195 (Nardelli, 1995). Crystal data C23H29NOIo Mr = 479.47 Monoclinic P21 a = 12.1510(10) ,~ b = 9.8460 (10) c = 10.6420 (10) fl = 107.14 (4) ° V = 1216.7 (2) ,~3 Z=2 D,, = 1.309 Mg m -3 Dm= 1.32 Mg m -3 Dm measured by flotation in ethanol/bromobenzene Data collection Enraf-Nonius CAD-4 diffractometer w-20 scans Absorption correction: none 3677 measured reflections 3677 independent reflections 2812 reflections with I > 2o'(/) Refinement Refinement on F z R(F) = 0.0485 wR(F z) - 0.1568 S = 1.094 3677 reflections 307 parameters H atoms not refined w = 1/[o'2(F 2) + (0.0997P) 2 + 0.0201P] where P = (F d + 2F2)/3 Mo Ko~ radiation A = 0.7107 ,~, Cell parameters from 25 reflections 0 - 5-10 ° # = 0.103 mm -I T = 293 (2) K Cube 0.4 x 0.4 x 0.4 mm Colourless Oma~ = 29.83 ° h = 0 ---* 17 k = 0 --* 13 l = - 14 ---* 14 3 standard reflections every 100 reflections intensity decay: none (A/O')max = -0.077 Apmax = 0.26 e ~,-3 Apmin = -0.33 e ,~-3 Extinction correction: none Scattering factors from International Tables for Crystallography (Vol. C) The authors thank Dr J. C. Palacios for supplying the crystals and the Junta de Andalucfa and DGICYT (PB92-0525-C02-02) for financial support. Lists of atomic coordinates, displacement parameters, structure factors and complete geometry have been deposited with the IUCr (Reference: BMI091). Copies may be obtained through The Managing Editor, International Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, England. References Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435- 436. Avalos, M., Babiano, R., Durfin, C. J., Jim6nez, J. L. & Palacios, J. C. (1992). J. Chem. Soc. Perkin Tram. 2, 2205-2215. Banic, Z., Kojic-Prodic, B., Kroon-Beterburg, L. & Keglevic, D. (1994). Carbohydr. Res. 259, 159-174. Boer, J. L. de & Duisenberg, A. J. M. (1984). Acta Cryst. A40, C-410. Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358. Enraf-Nonius (1989). CAD-4 Software. Version 5.0. Enraf-Nonius, Delft, The Netherlands. Nardelli, M. (1983). Acta Cryst. C39, 1141-1142. Nardelli, M. (1995). J. Appl. Cryst. 28, 659. Rettig, S. (1989). CELDIM in CAD-4 Software. Version 5.0. Enraf- Nonius, Delft, The Netherlands. Sheldrick, G. M. (1993). SHELXL93. Program for the Refinement of Crystal Structures. University of G6ttingen, Germany. Spek, A. L. (1994). PLATON. Molecular Geometry Program. Version of November 1994. University of Utrecht, The Netherlands. Stewart, J. M., Machin, P. A., Dickinson, C. W., Ammon, H. L., Heck, H. & Flack, H. (1976). The XRAF76 System. Technical Report TR- 446. Computer Science Center, University of Maryland, College Park, Maryland, USA. Vega, R., L6pez-Castro, A. & MS.rquez, R. (1986). Acta Cryst. C42, 1066-1068.