A novel glycoside lactone derivative with a 2-C-unsaturated diester substituent

Article abstract of DOI:10.1107/S0108270101015505

The title 4,6-O-benzylidene-α-D-glucopyranoside (systematic name: methyl 4-methoxy-2-oxo-8-phenyl-1,2,5a,6,9a,9b-hexahydro-4H,8H -7,9-dioxacyclopenta[c]chromene-3-carboxylate), C₁₈H₁₈O₈, has been synthesized from the reaction of methyl 4,6-O-benzylidene-α-D-2-ketoglucopyranoside with diethyl or dimethyl malonate. The compound adopts a chair-chair conformation. The newly formed five-membered ring is fused to the glucopyranoside ring along the C₂ - C₃ bond and is planar with an r.m.s. deviation of 0.0091 A.

Full text of DOI:10.1107/S0108270101015505

organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
ISSN 0108-2701
A novel glycoside lactone derivative
with a 2-C-unsaturated diester
substituent
Fuyi Zhang, Chen-Xia Du, Hong-Min Liu* and Yu Zhu
Figure 1
The molecular structure of (II) drawn with 50% probability displacement
ellipsoids.
Chemistry Department, Zhengzhou University, Zhengzhou 450052, People's
Republic of China
Correspondence e-mail: liuhm@public.zz.ha.cn
Received 15 June 2001
Accepted 21 September 2001
The title 4,6-O-benzylidene-ꢀ-d-glucopyranoside (systematic
name: methyl 4-methoxy-2-oxo-8-phenyl-1,2,5a,6,9a,9b-hexa-
hydro-4H,8H-7,9-dioxacyclopenta[c]chromene-3-carboxyl-
ate), C18H18O8, has been synthesized from the reaction of
methyl 4,6-O-benzylidene-ꢀ-d-2-ketoglucopyranoside with
diethyl or dimethyl malonate. The compound adopts a
chair±chair conformation. The newly formed ®ve-membered
ring is fused to the glucopyranoside ring along the C2ÐC3
Ê
bond and is planar with an r.m.s. deviation of 0.0091 A.
Comment
C-Branched monosaccharides are important chiral synthons in
both organic chemistry and biological substances, and some
have been found as components of living cells (Adinol® et al.,
1995, 1996). The stereoselective addition of a nucleophile to a
glycosidulose is an ef®cient route to the synthesis of C-bran-
ched sugars (Sato et al., 1994; Adinol® et al., 2000). In these
previous syntheses, the hydroxyl groups of the glycosiduloses
have been fully protected, since unprotected and partially
protected glycosiduloses have proven to be dif®cult to
synthesize selectively, are unstable in basic medium and
Figure 2
Packing diagram viewed down the b axis.
Compound (II) adopts a chair±chair conformation. Atoms
Ê
C11 and C5 are displaced by ꢀ0.6769 (2) and 0.7023 (6) A,
respectively, from the C6/C4/O4/O6 least-squares plane (r.m.s.
Ê
deviation 0.0022 A), giving a ¯attened chair conformation.
Ê
Atoms C2 and C5 deviate by ꢀ0.5444 (3) and 0.7216 (3) A,
respectively, from the C3/C4/C1/O5 plane (r.m.s. deviation
Ê
0.0055 A), resulting in a chair conformation which is more
distorted from a perfect chair conformation than the former,
as can be expected from the different substitution pattern. The
Ê
associated non-bonding distances are 2.786 (5) A for
Ê
C11Á Á ÁC5 and 2.763 (4) A for C5Á Á ÁC2. The ®ve-membered
usually exist in different forms (Liu & Tsuda, 1993, 1996a).
Thus, very little is known about the syntheses and structures of
C-branched glucopyranosides made from partially protected
2-ketoglucosides. We report here the X-ray structure of (II),
which was synthesized from the partially protected 2-keto-
glucoside (I) by reaction with diethyl or dimethyl malonate in
strong basic solution.
C2/C3/C8/C18/O3 ring is fused to the glucopyranoside ring
along the C3ÐC2 bond in an equatorial position at C3. The
Ê
short C2ÐC8 distance of 1.328 (5) A is typical for a double
bond having two carbonyl groups as neighbours, and the ®ve-
membered ring is consequently very planar, with an r.m.s.
Ê
deviation of 0.0091 A among the ®ve atoms. Atom C3 exhibits
ꢁ
Acta Cryst. (2001). C57, 1361±1362
# 2001 International Union of Crystallography
Printed in Great Britain ± all rights reserved 1361

organic compounds
Ê
the largest out-of-plane displacement of 0.0124 (2) A and C18
Ê
is closest to the mean plane [0.0028 (2) A]. In addition, the
Re®nement
Re®nement on F2
R[F2 > 2ꢃ(F2)] = 0.054
wR(F2) = 0.103
S = 1.13
2608 re¯ections
w = 1/[ꢃ2(Fo2) + (0.0456P)2
+ 0.0022P]
phenyl ring is approximately parallel to the C6/C4/O4/O6 and
C5/O5/C2/C3 least-squares planes, forming interplanar angles
of 9.7 (2) and 5.3 (3)ꢂ, respectively. Similarly, the ®ve-
membered C2/C3/C8/C18/O3 ring is inclined at angles of
34.98 (9), 25.89 (8) and 29.82 (8)ꢂ to the C12±C17, C4/C6/O4/
O6 and C2/C3/C5/O5 planes, respectively. The absolute
structure was deduced based on compound (I), which is
known to be an ꢀ-d-2-ketoglucopyranoside. As shown in the
packing diagram (Fig. 2), the molecules stack along the b
direction in an ef®cient manner.
where P = (Fo2 + 2Fc2)/3
(Á/ꢃ)max = 0.006
Ê ꢀ3
Áꢄmax = 0.17 e A
Ê ꢀ3
236 parameters
H-atom parameters constrained
Áꢄmin = ꢀ0.14 e A
Extinction correction: SHELXL97
Extinction coef®cient: 0.0112 (11)
Ê
All H atoms were ®xed at ideal positions (CÐH = 0.93±0.98 A)
2
with a common isotropic displacement parameter (Uiso = 0.08 A ).
Ê
Data collection: R-AXIS Software (Rigaku, 1997); cell re®nement:
R-AXIS Software; data reduction: R-AXIS Software; program(s) used
to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to
re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:
TEXSAN (Molecular Structure Corporation, 1992).
Experimental
The title compound was synthesized by an aldol condensation of
compound (I) (400 mg, 1.43 mmol; Liu & Tsuda, 1996b) in CHCl3
with diethyl or dimethyl malonate (5.62 mmol) in the presence of
sodium methoxide (516 mg, 9.56 mmol). The product (350 mg) was
obtained as colourless crystals melting at 443±445 K after recrys-
tallization from methanol/acetone.
This work was supported by the NNSF of China (project
296772030) and HEYSF of HN.
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: DA1200). Services for accessing these data are
described at the back of the journal.
Crystal data
References
C18H18O8
Mr = 362.32
Mo Kꢀ radiation
Cell parameters from 188
re¯ections
Adinol®, M., Barone, G., Festa, P., Guariniello, L. & Iadonisi, A. (2000).
Tetrahedron Lett. 41, 4981±4985.
Orthorhombic, P212121
Ê
a = 22.469 (5) A
Ê
ꢁ = 2.8±26.0ꢂ
Adinol®, M., Corsaro, M. M., De Castro, C., Evidente, A., Lanzetta, R.,
Mangoni, L. & Parrilli, M. (1996). Carbohydr. Res. 284, 111±118.
Adinol®, M., Corsaro, M. M., De Castro, C., Lanzetta, R., Parrilli, M.,
Evidente, A. & Lavermicocca, P. (1995). Carbohydr. Res. 267, 307±311.
Liu, H.-M. & Tsuda, Y. (1993). Chem. Pharm. Bull. 41, 491±501.
Liu, H.-M. & Tsuda, Y. (1996a). Chem. Pharm. Bull. 44, 80±87.
Liu, H.-M. & Tsuda, Y. (1996b). Chem. Pharm. Bull. 44, 88±90.
Molecular Structure Corporation (1992). TEXSAN. MSC, 3200 Research
Forest Drive, The Woodlands, TX 77381, USA.
Rigaku (1997). R-AXIS Software. Rigaku Corporation, Tokyo, Japan.
Sato, K., Bokura, M., Moriyaman, H. & Igarashi, T. (1994). Chem. Lett. 1, 37±
40.
Sheldrick, G. M. (1990). Acta Cryst. A46, 467±473.
Sheldrick, G. M. (1997). SHELXL97. University of Gottingen, Germany.
b = 4.6467 (9) A
Ê
ꢂ = 0.11 mmꢀ1
T = 291 (2) K
Prism, colorless
0.30 Â 0.30 Â 0.20 mm
c = 16.501 (3) A
3
Ê
V = 1722.8 (6) A
Z = 4
Dx = 1.397 Mg mꢀ3
Data collection
Rigaku R-AXIS-IV Imaging Plate
diffractometer
Oscillation frame scans
2635 measured re¯ections
2608 independent re¯ections
2244 re¯ections with I > 2ꢃ(I)
Rint = 0.045
max = 27.5ꢂ
ꢁ
h = 0 ! 29
k = ꢀ6 ! 6
l = 0 ! 20
È
ꢁ
1362 Zhang, Du, Liu and Zhu
C18H18O8
Acta Cryst. (2001). C57, 1361±1362