698
Q. Tian, X.-M. Zhu, and J.-S. Yang
resin was washed with acetone. The combined filtrate and washings were con-
centrated under reduced pressure. The residue was subjected to column
chromatography using petroleum ether–EtOAc as the eluant to afford the cor-
responding products. Following the same reaction conditions, O- and S-
nucleophiles gave the corresponding 2,3-unsaturated glycosides as summar-
ized in Table 2. Glycosides 1b–7b, 9b, 10b, 12b, 14b, and 15b are known
1
compounds, and their H and 13C NMR data matched the reported data in
the cited references (Table 2). Spectral data of new compounds that are not
reported are listed next.
Data
Methyl O-(40,60-di-O-acetyl-20,30-dideoxy-a-D-erythro-hex-20-enopyranosyl)-
(1 ! 3)-2-O-benzoyl-4,6-O-benzylidene-a-D-glucopyranoside (8b). From 1
(54.5 mg), colorless syrup, 71.8 mg (60%); Rf 0.3 (3:1, petroleum ether–
1
EtOAc); [a]2D1C þ 60.1 (c 1.5, CHCl3); H NMR (400 MHz, CDCl3): dH 1.90
(s, 3H, COCH3), 2.10 (s, 3H, COCH3), 3.43 (s, 3H, OCH3), 3.75–4.00
(m, 6H, H-6a, H-6b, H-5, H-6a0, H-6b0 and H-50), 4.34 (dd, J3,4 10.0, J4,5
4.8 Hz, 1H, H-4), 4.59 (t, J2,3, J3,4 9.6 Hz, 1H, H-3), 5.00 (d, J1,2 3.6 Hz, 1H,
0
H-1), 5.20 (dd, J1,2 3.6, J2,3 10.0 Hz, 1H, H-2), 5.24 (dd, J3 , 4 1.6, J4 ,5
0
0
0
9.6 Hz, 1H, H-40), 5.54 (s, 1H, H-10), 5.60 (s, 1H, PhCH), 5.78 (d, J2 ,3
0
0
11.6 Hz, 1H, H-20), 5.82 (dt, J2 ,3 10.4, J3 ,4 2.0 Hz, 1H, H-30), 7.34–8.14
(m, 10H, aromatic); 13C NMR (100 MHz, CDCl3): dC 170.8, 170.0
(2 ꢀ COCH3), 165.8 (PhCO), 137.0, 133.4, 129.8, 129.7, 129.1, 128.7, 128.5,
128.3, 128.2, 127.6, 126.3, 126.0 (aromatic, C-20 and C-30), 101.6 (PhCH),
98.0 (C-1), 94.3 (C-10), 82.7 (C-3), 72.4 (C-2), 71.9 (C-4), 69.0 (C-6), 66.4
(C-40), 64.7 (C-50), 62.4 (C-5), 62.1 (C-60), 55.4 (OCH3), 20.7, 20.6
(2 ꢀ COCH3); HR ESI-MS: calcd. for C31H34O12 [M þ Na]þ: 621.1948;
found: 621.1937. Anal. calcd for C31H34O12: C, 62.20; H, 5.73þ; found: C,
62.39; H, 5.79.
0
0
0
0
Allyl O-(40,60-di-O-acetyl-20,30-dideoxy-a-D-erythro-hex-20-enopyranosyl)-
(1 ! 6)-2,3,4-tri-O-benzyl-a-D-glucopyranoside (11b). From 1 (54.5 mg),
colorless syrup, 122.7 mg (89%); Rf 0.31 (3:1, petroleum ether–EtOAc);
[a]2D1 þ 34.4 (c 18.2, CHCl3); H NMR (400 MHz, CDCl3): dH 1.99 (s, 3H,
1
COCH3), 2.06 (s, 3H, COCH3), 3.53 (dd, J1,2 3.6, J2,3 9.6 Hz, 1H, H-2),
3.59 (t, J2,3, J3,4 9.2 Hz, 1H, H-3), 3.71 (d, J4,5 10.8 Hz, 1H, H-5), 3.83
(d, J3,4 9.6 Hz, 1H, H-4), 3.98–4.06 (m, 5H, OCH2aCH55CH2, H-6a, H-6b,
H-50, and H-6b0), 4.13–4.20 (m, 2H, OCH2bCH55CH2 and H-6a0), 4.64
(d, J 10.8 Hz, 1H, PhCH2), 4.66 (d, J 12.4 Hz, 1H, PhCH2), 4.77 (d, J
14.4 Hz, 1H, PhCH2), 4.80 (d, J
4.4 Hz, 1H, H-1), 4.81 (d, J 12.0 Hz,
1,2
1H, PhCH2), 4.93 (d, J 10.8 Hz, 1H, PhCH2), 5.00 (d, J 10.8 Hz, 1H,
PhCH2), 5.10 (s, 1H, H-10), 5.22 (d, J 10.0 Hz, 1 H, OCH2CH55CH2a),
5.29 (s, 1H, H-40), 5.33 (d, J 10.8 Hz, 1H, OCH2CH55CH2b), 5.85 (s, 2H,