Crystal and molecular structure of (?)-1,2-O-isopropylidene-3-O-methyl-7,8-dideoxy-?-l-glycero-d-gluco-non-7-enofuranurono-9,6-lactone, C13H18O7

Journal of Crystallographic and Spectroscopic Research, Vol. 2 I, No. 3, 1991

Crystal and molecular structure of (-)-l,2-O-isopropylidene3-O-methyl-7,8-dideoxy-p-L-glycero-D-gluco-non-7enofuranurono-9,6-1actone, C13H1807 Giovanna Gasparri Fava, *'1 Marisa Ferrari Belicchi, ~ Daniele Belletti, t Giovanni Casiraghi, z and Gloria Rassu z

Received May 11, 1990; accepted August 21, 1990

The crystal structure of the title lactone, CI3H1807, has been determined by single crystal diffraction methods. The compound crystallizes in the monoclinic space group P21 with a = 13.231(2), b = 10.248(2), c = 5.348(1) A,/3 = 96.66(2) ~ and Z = 2. A total of 1055 reflection intensities were recorded on a Siemens AED single-crystal diffractometer (Cu Kc~ radiation) at room temperature. The structure was solved by direct methods and electron density calculations. Full-matrix least-squares refinement gave R = 0.055 for 946 unique reflections above 2~(1). The absolute configuration of the six chiral carbon atoms was deduced as 4S, 5R, 6R, 7S, 9R, 10R (crystallographic numbering corresponds to C-6, 5, 4, 3, 2, 1 in the title compound). An intermolecular O - - H - - - O hydrogen bond joins the molecules in chains which run along the twofold screw axis.

presence o f BF 3 etherate, a nine-carbon 7-substituted butenolide, late assigned as 3, was obtained with spectacular diasteroselectivity (96% ds), accompanied by a marginal amount (less than 4%) o f a second epimeric compound (Casiraghi et al., 1990a). Since neither IH and ~3C N M R analyses nor chemical and chiroptical correlations to known substances proven valuable to establish firmly the relative stereodisposition o f the C(4) and C(5) stereogenic centers newly emerged during the carbon-carbon bond forma-

Introduction

Recently, as part o f a program of study directed towards the synthesis and structural analysis o f highercarbon sugars and long-chain carbon-glycosides, we exploited 2-(tfimethylsiloxy)furan (1) as a four-carbon homologative reagent o f chiral aldehydo-sugar precursors (Casiraghi et al., 1989). In particular, when 1 was reacted in dichloromethane with dialdofuranose 2 in the OMe _.--

OH

OHC +

~

Me

Me3SiO

BF3.0Et2/CHaCI2

Y-

Me I

L_Me

O

2

O/- I 5

Me

Scheme 1

11stituto di Chimica Generale dell'Universitg and Centro di Studio per la Struttufistica Diffrattometrica del CNR, Viale delle Scienze 1, 1-43100 Parma, Italy. 2Dipartimento di Chimica dell'Universitg and Istituto per l'Applicazione delle Tecniche Chimiche Avanzate ai Problemi Agrobiologici del CNR, Via Vienna 2, 1-07100 Sassari, Italy.

tion, we considered unambiguous determination o f the structure of the title lactone by X-ray analysis necessary. The current study confirms both the structure and the stereochemistry o f 3, a useful candidate for the synthesis o f quite rare nine-carbon sugar derivatives. 261 0277-8068/91/0600-0261$06.50/0 9 1991 PlenumPublishingCorporation

262

Fava, Belicchi, Belletti, Casiraghi, and Rassu Table 1. Fractional atomic coordinates (• 104) for nonhydrogen

Experimental

atoms

The butenolide 3 was synthesized according to the reaction shown in Scheme 1 (Casiraghi et al., 1990a) and purified by flash chromatography on silica gel using 85 % ethyl acetate in hexanes. Crystals were grown by slow evaporation of an ether-hexanes solution; m.p. 127-128~ [a] 2~ = - 8 0 . 0 ~ (c 0.5, CHCI3). Analysis: calcd, for C13H1807: C, 54.54; H, 6.34. Found: C, 54.20; H, 6.38.

Crystal data Monoclinic P21 No. 4, a = 13.231(2), b 10.248(2), c = 5.348(1) A , /3 = 94.66(2) ~ V 722.75 A 3, Z = 2, M for CI3H1807 : 286.28, Dc 1.32 Mg m -3, X(Cu Kcr = 1.54056 A , t~(Cu Kc0 0.87 mm -1, F(000) = 304, room temperature.

= = = =

O(1) 0(2) 0(3) 0(4) 0(5) 0(6) 0(7) C(1) C(2) C(3) C(4) C(5) C(6) C(7) C(8) C(9) C(10) C(ll) C(12) C(13)

x/a

y/b

z/c

912(5) 1742(4) 1029(4) 2207(4) 3278(4) 4554(3) 5017(4) 893(7) 86(6) 432(7) 1503(6) 1591(6) 2671(5) 2843(5) 2069(8) 3929(5) 4116(6) 5383(5) 5636(7) 6260(7)

9549(0) 8132(9) 5649(10) 3269(9) 5705(9) 4303(8) 5498(9) 8820(11) 8489(13) 7634(14) 7281(11) 5848(11) 5475(11) 4035(11) 1945(12) 3836(10) 4848(11) 4998(10) 6148(12) 4075(13)

4396(14) 7069(11) 5879(13) 8824(13) 10153(9) 6366(7) 9863(9) 6181(21) 7857(20) 9527(20) 9112(18) 8242(17) 7818(14) 7304(14) 7979(25) 8255(13) 10363(12) 7566(13) 6021(16) 8235(23)

Data collection Colorless prismatic crystal, approximately 0.06 • 0.42 x 0.16 mm, Siemens AED Single-crystal diffractometer, Ni-filtered Cu Kc~ radiation, cell parameters from least-square fit of 30 reflections (0 > 15 ~ accurately measured on the diffractometer, one check reflection measured every 50 counts without significant variation, profile analysis with Lehmann and Larsen (1974) procedure modified by Belletti et al. (1988); 2.5 < 0 < 60 ~ Lp correction, absorption ignored, - 17 < h < 17, 0 < k < 13, 0 < l < 8, 1055 reflections collected, 946 unique observed at 2cffI) level (Rinr = 0.013).

Results and discussion Figure 1 shows the molecule and numbering scheme while Figure 2 is a c-axis projection of the unit cell. Table 2 gives bond distances and angles, and selected torsion angles. The X-ray diffraction study clearly established that the compound possess 4S, 5R,

C(8)

Structure solution and refinement The structure was solved by direct methods. Leastsquares refinement of positional and anisotropic thermal parameters for heavy atoms (isotropic H atoms located in a A F map but not refined) gave final R = 0.055, R G = 0.053, S = 0.7, A/o (max) = 0.066, residual electron density - 0 . 1 0 < AO < + 0.08 e A - 3 . Scattering factors were taken from SHELX 76 (Sheldrick, 1976). All calculations were performed on a GOULD 6040 Powernode computer of the Centro di Studio per la Stmtturistica Diffrattometrica del CNR (Parma, Italy) using the PARST (Nardelli, 1983), ORTEP (Johnson, 1976), Pluto (Motherwell, 1976), SHELX 86 (Sheldrick, 1985), SHELX 76 programs. Final atomic parameters are listed in Table 1.

(~ o(3)

(~)

0(2) ~ 1 3 ) 0(51 0 ( 5 ) ~ 0 ( 7

#~-~0(~)C(1)

~

C(12)

) z~

~)

Fig. 1, ORTEPview of the molecule in its correct absolute configuration showing the atomic numbering scheme. Thermal ellipsoids enclose 40% of probability and the hydrogen atoms are drawn with an arbitrary diameter.

Structure of

C13H1807

263

Fig. 2. Projectionof the structureon the (001) plane. 6R, 7S, 9R, 10R absolute configuration being 2 our starting sugar. In fact, since the configurations of C(6), C(7), C(9), and C(10) (crystallographic numbering) corresponding to the unaltered C-4, 3, 2, 1 atoms of the starting sugar (or 2), are R, S, R, R, it can be deduced that the absolute configuration at C(5) and C(4) (C-5 and C-6) is R and S, respectively. The torsion angle H(5)--C(5)--C(4)--H(4) is 75.2(-) ~ and the H(4)--H(5) bond distance is 2.49 A. The c~,/3-unsaturated 7-butyrolactone ring is nearly planar, with a maximum deviation of 0.03 A for C(4). The values of O(2)--C(4) and O(2)--C(1) bond distances are in accordance with those reported for other 7-butyrolactones (Casiraghi et al., 1990b; Matijasic et al., 1988). The internal angles are in the range 103.5(8)110.2(9) ~ Their mean value (108) ~ is equal to the calculated angle in a regular pentagon. The dihedral angles between the lactone ring and the planes of the furanose and the isopropylidene tings are 96.7(3) and 100.2(3) ~ respectively. The furanose and the isopropylidene tings show a twist and an envelope conformation respectively (the first with the twist axis through C(10)); the puckering parameters are q2 0.341(8) A , (~2 = 159(1)~ =

q2 = 0.203(8) A , ~b2 = -149(2) ~ respectively (Cremer and Pople, 1975). Comparison with similar structures where an isopropylidene ring is fused to a furanose ring shows that the bond distance O(7)--C(11) is longer than O(7)--C(10) and O(5)--C(10), as found by Sheldrick et al. (1983) in a large number of works, using data extracted from the Cambridge Crystallographic Data File (Kennard et al., 1975). The two rings are twisted about their common bond such that the torsion angles formed by 0 ( 5 ) - C(10)--C(9)--C(7) and O(6)--C(9)--C(10)--O(7) are - 12.3(9) and - 18.0(8) ~ respectively, while two torsion angles O(5)--C(10)--C(9)--O(6) and C(7)-C(9)--C(10)--O(7) are 100.3(7) and -130.6(7) ~ The least-squares planes through each of the two rings form a dihedral angle of 69.1(3) ~ The structure is polymeric being made up by chains of molecules connected by a strong intermolecular hydrogen bond O ( 3 ) - - H ( 3 0 ) . 9 .O(1) ( - x , y + 1/2, - z ) = 2.798(9) A. The chains, which run along the twofold screw axis, are joined together by van der Waals interactions.

264

Fava, Belicchi, Belletti, Casiraghi, and Rassu Table 2. Bond distances (A), angles (~ and selected torsion angles (~

O(1)--C(1) O(2)--C(1) O(2)-- C(4) O(3)--C(5) O(4)--C(7) O(4)--C(8) O(5)-- C(6) O(5)--C(10) O(6)--C(9) O(6)--C(11) 0(7) C(10) C(1)--0(2)--C(4) C(7)--O(4)--C(8) C(6)--O(5)--C(10) C(9)--O(6)--C(11) C(10)--O(7)--C(11) 0(1)--C(1)--0(2) 0(2)--C(1)--C(2) 0(1)--C(1)--C(2) C(1)--C(2)--C(3) C(2)--C(3)--C(4) 0(2)--C(4) --C(3) C(3)--C(4) C(5) 0 ( 2 ) - c ( 4 ) - c(5) 0(3)-c(5)-c(4) C(4)--C(5)--C(6) O(3)--C(5)--C(6) O(5)-- C(6) -- C(5) C(8)--O(4)--C(7)--C(6) C(8)--O(4)--C(7)--C(9) C(11)--O(6)--C(9)--C(7) C(3)--C(4)-- C(5)-- 0(3) C(3)--C(4)--C(5)-- C(6) O(2)--C(4)--C(5)--C(6) H(4)--C(4)--C(5)-- H(5) H(5)--C(5)--C(6)--H(6)

1.214(13) 1.378(12) 1.453(13) 1.428(11) 1.447(12) 1.437(16) 1.448(9) 1.411(11) 1.438(9) 1.417(10) 1.410(11) 110.2(6) 113.6(8) 110.1(6) 108.5(5) 109.9(6) 121.2(8) 106.3(8) 132.5(9) 109.6(8) 110.2(9) 103.5(8) 111.7(8) 108.5(7) 110.8(8) 112.3(8) 105.2(7) 107.1 (6) 162.3(8) -86.3(9) 138.3(7) 63(1) - 179.9(8) 67(1) 75.2(-) - 171.1(-)

References

Belletti, D., Cantoni, A., and Pasquinelli, G. (1988) Gestione on line di diffrattometro a cristallo singolo Siemens AED con sistema IBM PS2/30, Centro di Studio per la Strntturistica Diffrattometrica del CNR, Parma, Italy: Internal report 1/88. Casiraghi, G., Colombo, L., Rassu, G., and Spanu, P. (1989) Tetrahed. Lett. 30, 5325. Casiraghi, G., Colombo, L., Rassn, G., and Spanu, P. (1990a) J. Org. Chem. 55, 2565. Casiraghi, G., Colombo, L., Rassu, G., and Spanu, P., Gasparri Fava, G., and Ferrari Belicchi, M. (1990b) Tetrahedron 46, 5807. Cremer, D., and Pople, J. A. (1975) J. Am. Chem. Soc. 97, 1354. Johnson, C. K. (1976) ORTEPFortran thermal-ellipsoid program for crystal structure illustrations. Report ORNL-5138 (Oak Ridge National Laboratory, Oak Ridge, Tenn.). Lehmann, M. S., and Larsen, F. K. (1974) Acta Crystallogr. A30, 580.

0 ( 7 ) - c ( 1 l) c(1)-c(2) c ( 2 ) - c(3) c ( 3 ) - c(4) c(4)-c(5) C(5)--C(6) C(6) C(7) C(7)--C(9) C(9)--C(10) C(l 1)--C(12) C(l 1)--C(13) C(5)--C(6)--C(7) O(5) C(6)--C(7) O(4)--C(7) C(6) C(6)--C(7) C(9) 0(4) -- C(7) --C(9) O(6)-- C(9)-- C(7) C(7)--C(9)-- C(I 0) 0(6)--C(9)--C(10) O(7)--C(10)--C(9) O(5)--C(10)--C(9) O(5)--C(10)--O(7) O(6)-- C(11)--O(7) O(7)--C(l 1)--C(13) 0(7)--C(11)--C(12) 0(6) C(I 1)--C(13) O(6)--C(I 1)--C(12) C(12)--C(11)--C(13) O(3)--C(5)--C(6)--O(5) O(3)--C(5)--C(6)--C(7) C(5)--C(6)-- C(7)--O(4) C(7)--C(9)--C(10)--O(7) C(7)--C(9)--C(10)--O(5) H (6) -- C(6)-- C(7) -- H(7) H(7)--C(7) C(9)--H(9) H(9)--C(9)-- C(10)-- H(10)

1.450(10) 1.488(14) 1.308(17) 1.496(12) 1.548(16) 1.514(1 I) 1.522(15) 1.499(10) 1,537(12) 1.493(15) 1.518(14) 115.4(7) 103.4(6) 108.8(6) 102.9(7) 108.7(7) 107.8(6) 104.4(6) 102.9(6) 105.5(6) 106.5(6) 111.2(8) 105.2(6) 108.8(7) 107.2(7) 110.0(8) 110.3(6) 114.9(7) 178.1(7) -67.4(9) - 37(1) - 130.6(7) -12.3(9) - 52.2(-) -84.4(-) -25.3(-)

Kennard, O., Watson, D. G., Allen, F. H., Motherwell, W. D. S., Town, W., and Rogers, J. R. (1975) Chem. Br. l l , 213. Matijasic, I., Bocelli, G., Ugozzoli, F., and Sgarabotto, P. (1988) Acta Crystallogr. C44, 159. Motherwell, W. D. S. (1976) PLUTO,A program for plotting molecular and crystal structures (University Chemical Laboratory, Cambridge, England). Nardelli, M. (1983) Comput. Chem. 7, 95. Sheldrick, B., Mackie, W., and Akrigg, D. (1983) Acta Crystallogr. C 39, 1259. Sheldrick, G. M. (1976) SHELX-76. A program for crystal structure determination (University Chemical Laboratory, Cambridge, England). Sheldrick, G. M. (1985) SHELX-86. Crystallographic computing 3, Oxford University press. Structure factor data, anisotropic thermal parameters of heavy atoms, and hydrogen coordinates with their isotropic parameters have been deposited with the British Library, Boston Spa, Wetherby, West Yorkshire, UK as supplementary publication No. 63137 (9 pages).