7118
H. Ohtake et al. / Tetrahedron 56 (2000) 7109–7122
PhCH2), 4.54 (1H, d, J11.6 Hz, PhCH2), 4.61 (1H, d,
J11.3 Hz, PhCH2), 4.63 (1H, d, J11.3 Hz, PhCH2),
4.68 (1H, d, J11.6 Hz, PhCH2), 4.77 (1H, d, J11.3 Hz,
PhCH2), 4.80 (1H, d, J11.3 Hz, PhCH2), 7.21–7.36 (20H,
m, PhH); 13C NMR (400 MHz, CDCl3) d 15.9, 22.5, 23.4,
30.0, 69.8, 70.3, 71.1, 71.7, 73.3, 73.4, 73.8, 74.3, 76.6,
78.8, 80.2, 100.4, 127.4, 127.5, 127.6, 127.7, 128.1,
128.2, 128.3, 128.3, 128.3, 128.5, 128.8, 138.4 (2C),
138.4, 138.6; MS (EI) m/z 640 (M), 625 (MϪMe),
549 (MϪBn), 536 (MϪHOCH2C (Me)2CH2OH); HRMS
(EI) calcd for C40H48O7 640.3400, found 640.3399.
and 7c were also prepared with this procedure in 90 and
93% yields, respectively.
3,4,5,7-Tetra-O-benzyl-1-deoxy-2-O-(3-tert-butyldimethyl-
silyloxy-2,2-dimethylpropyl)-d-gluco-hept-1-enitol (7a).
Colorless syrup; [a]2D8ϩ30.4Њ (C1.1, CHCl3); IR (neat,
cmϪ1) 3486, 3032, 2955, 2930, 2859, 1624, 1497, 1455,
1
1397, 1362; H NMR (400 MHz, CDCl3) d 0.00 (3H, s,
MeSi), 0.01 (3H, s, MeSi), 0.87 (3H, s, Me), 0.88 (9H, s,
t-BuSi), 0.89 (3H, s, Me), 2.87 (1H, d, J4.9 Hz, OH), 3.33
(1H, d, J9.8 Hz, –OCH2C (Me)2–), 3.35 (1H, d, J
9.8 Hz, –OCH2C (Me)2–), 3.39 (1H, d, J9.2 Hz,
–OCH2C (Me)2–), 3.46 (1H, d, J9.2 Hz, –OCH2C
(Me)2–), 3.56 (1H, dd, J10.0, 5.7 Hz, H-7), 3.60 (1H,
dd, J10.0, 3.6 Hz, H-7), 3.65 (1H, dd, J6.7, 3.4 Hz,
H-5), 3.94–3.99 (1H, m, H-6), 4.03 (1H, dd, J5.9,
3.4 Hz, H-4), 4.19 (1H, d, J2.0 Hz, H-1), 4.19 (1H, d,
J5.9 Hz, H-3), 4.22 (1H, d, J2.0 Hz, H-1), 4.41 (1H, d,
J11.3 Hz, PhCH2), 4.47 (1H, d, J11.9 Hz, PhCH2), 4.50
(1H, d, J11.6 Hz, PhCH2), 4.51 (1H, d, J11.9 Hz,
PhCH2), 4.53 (1H, d, J11.6 Hz, PhCH2), 4.66 (1H, d,
J11.3 Hz, PhCH2), 4.66 (1H, d, J11.3 Hz, PhCH2),
4.83 (1H, d, J11.3 Hz, PhCH2), 7.18–7.36 (20H, m,
PhH); 13C NMR (400 MHz, CDCl3) d Ϫ5.5, Ϫ5.5, 18.3,
21.7 (2C), 25.8 (3C), 36.5, 68.7, 70.8, 71.0, 71.3, 72.8,
73.3, 73.4, 74.7, 78.2, 79.2, 81.0, 85.2, 127.4, 127.4,
127.5, 127.6, 127.7, 127.8, 128.0, 128.0, 128.1, 128.2,
128.2, 128.2, 128.3, 128.3, 128.5, 138.2, 138.3, 138.5,
138.5, 158.8; MS (EI) m/z 754 (M), 663 (MϪBn), 536
(MϪTBDMSOCH2C (Me)2CH2OH); HRMS (EI) calcd for
C46H62O7Si 754.4265, found 754.4269.
3,4,5,7-Tetra-O-benzyl-1-deoxy-d-gluco-2-heptulose pro-
pane-1,3-diyl acetal (4d). Colorless syrup; [a]2D5Ϫ25.5Њ
(C1.2, CHCl3); IR (neat, cmϪ1) 3432, 2923, 2870, 1588,
1
1455, 1385; H NMR (400 MHz, CDCl3) d 1.40 (1H, m,
–CH2CH2CH2–), 1.46 (3H, s, Me), 1.85 (1H, m,
–CH2CH2CH2–), 3.10 (1H, d, J5.2 Hz, OH), 3.54–3.61
(2H, m), 3.69–3.76 (3H, m), 3.84–3.98 (3H, m), 4.06 (1H,
m, H-6), 4.27 (1H, dd, J5.2, 3.4 Hz, H-4), 4.49 (1H, d,
J12.2 Hz, PhCH2), 4.53 (1H, d, J12.2 Hz, PhCH2), 4.55
(1H, d, J11.3 Hz, PhCH2), 4.59 (1H, d, J11.3 Hz,
PhCH2), 4.65 (1H, d, J11.3 Hz, PhCH2), 4.65 (1H, d,
J11.6 Hz, PhCH2), 4.78 (1H, d, J11.3 Hz, PhCH2),
4.80 (1H, d, J11.6 Hz, PhCH2), 7.20–7.35 (20H, m,
PhH); 13C NMR (400 MHz, CDCl3) d 16.3, 25.7, 59.2,
59.7, 71.0, 71.8, 73.3, 73.3, 73.8, 74.2, 76.6, 79.0, 80.7,
100.3, 127.3, 127.5, 127.7, 128.0, 128.2, 128.3, 128.5,
128.7, 138.3, 138.4 (2C), 138.6; MS (EI) m/z 612 (M),
597 (MϪMe), 536 (MϪHOCH2CH2CH2OH), 521
(MϪBn); HRMS (EI) calcd for C38H44O7 612.3087, found
612.3076.
3,4,5,7-Tetra-O-benzyl-1-deoxy-2-O-(3-tert-butyldimethyl-
silyloxy-2,2-dimethylpropyl)-d-galacto-hept-1-enitol (7b).
Colorless syrup; [a]2D4Ϫ13.0Њ (C1.1, CHCl3); IR (neat,
cmϪ1) 3503, 3032, 2955, 2930, 2859, 1456; 1H NMR
(400 MHz, CDCl3) d 0.01 (3H, s, MeSi), 0.01 (3H, s,
MeSi), 0.88 (9H, s, t-BuSi), 0.91 (3H, s, Me), 0.92 (3H, s,
Me), 3.17 (1H, d, J4.9 Hz, OH), 3.35 (1H, d, J9.5,
–OCH2C (Me)2–), 3.38 (1H, d, J9.5, –OCH2C (Me)2–),
3.40 (1H, d, J9.2, –OCH2C (Me)2–), 3.46 (1H, dd, J9.5,
6.1, H-7), 3.51 (1H, d, J9.2, –OCH2C (Me)2–), 3.52 (1H,
dd, J9.5, 5.9, H-7), 3.69 (1H, dd, J5.4, 1.5, H-5), 4.02
(1H, d, J5.4, H-3), 4.06 (1H, t, J5.4, H-4), 4.10–4.14
(1H, m, H-6), 4.22 (1H, d, J2.1, H-1), 4.32 (1H, d, J
11.6, PhCH2), 4.34 (1H, d, J11.9, PhCH2), 4.35 (1H,
d, J2.1, H-1), 4.37 (1H, d, J11.6, PhCH2), 4.39 (1H,
d, J11.9, PhCH2), 4.49 (1H, d, J11.9, PhCH2), 4.66
(1H, d, J11.0, PhCH2), 4.72 (1H, d, J11.9, PhCH2),
4.76 (1H, d, J11.0, PhCH2), 7.18–7.35 (20H, m,
PhH); 13C NMR (400 MHz, CDCl3) d Ϫ5.5, Ϫ5.5,
18.3, 21.8 (2C), 25.9 (3C), 36.5, 68.7, 70.0, 70.9,
71.4, 72.8 (2C), 73.1, 75.5, 76.8, 80.2, 80.2, 84.7,
127.5, 127.5, 127.6, 127.6, 127.7, 128.0, 128.2, 128.3,
128.3, 128.3, 128.3, 138.2, 138.2, 138.3, 138.3, 158.6;
MS (EI) m/z 754 (M), 663 (MϪBn), 536 (MϪBnϪ
TBDMSOCH2C (Me)2CH2OH); HRMS (EI) calcd for
C46H62O7Si 754.4265, found 754.4257.
3,4,5,7-Tetra-O-benzyl-1-deoxy-d-gluco-2-heptulose
ethane-1,2-diyl acetal (4e). Colorless syrup; [a]2D73.7Њ
(C1.1, CHCl3); IR (neat, cmϪ1) 3484, 3031, 2880, 1497,
1455, 1397, 1360; 1H NMR (400 MHz, CDCl3) d 1.40 (3H,
s, Me), 3.01 (1H, d, J4.3 Hz, OH), 3.60–3.64 (3H, m),
3.74–3.99 (7H, m), 4.50 (1H, d, J11.9 Hz, PhCH2), 4.55
(1H, d, J11.0 Hz, PhCH2), 4.55 (1H, d, J11.0 Hz,
PhCH2), 4.59 (1H, d, J11.9 Hz, PhCH2), 4.62 (1H, d,
J11.3 Hz, PhCH2), 4.70 (1H, d, J11.3 Hz, PhCH2),
4.72 (1H, d, J11.3 Hz, PhCH2), 4.80 (1H, d, J11.3 Hz,
PhCH2), 7.22–7.36 (20H, m, PhH); 13C NMR (400 MHz,
CDCl3) d 21.1, 64.4, 64.8, 71.0, 71.4, 73.3, 73.4, 73.9, 74.0,
77.8, 77.8, 79.7, 110.9, 127.4, 127.6, 127.6, 127.8, 128.1,
128.2, 128.2, 128.3, 128.3, 128.4, 138.2, 138.3, 138.3,
138.5; MS (EI) m/z 598 (M), 583 (MϪMe), 537
(MϪOCH2CH2OH), 507 (MϪBn); HRMS (EI) calcd for
C37H42O7 598.2931, found 598.2949.
Protection of 1Њ-alcohols of the enol ethers 5a–c
To a solution of 5a (2.57 g, 4.0 mmol) in DMF (40 ml) was
added Et3N (2.8 ml, 20 mmol), 4- (dimethylamino)pyridine
(48 mg, 0.40 mmol), and TBDMSCl (1.21 g, 8.0 mmol)
successively. The mixture was stirred at room temperature
under Ar for 2 h, and then poured into a mixture of ether
(300 ml) and diluted water (300 ml). The organic layer was
washed twice with diluted water (300 ml×2), dried over
Na2SO4, and then evaporated. The residue was applied to
a silica gel column chromatography (ether–hexane 1:4) to
afford 7a as colorless syrup (2.74 g, 91%). Compounds 7b
3,4,5,7-Tetra-O-benzyl-1-deoxy-2-O-(3-tert-butyldimethyl-
silyloxy-2,2-dimethylpropyl)-d-manno-hept-1-enitol (7c).
Colorless syrup; [a]D23ϩ3.9Њ (C1.3, CHCl3); IR (neat,
cmϪ1) 3459, 3032, 2955, 2930, 2859, 1624, 1497, 1455,