1128
Vol. 52, No. 9
4c Oil; IR (liquid film) nmax 3340 (OH), 1742 (CꢁO) cmꢂ1 1H-NMR
;
under reduced pressure to give a crude residue, which was purified with sil-
ica gel column chromatography (eluent, 2% MeOH–CH2Cl2) to afford 8
(0.955 g, 85%).
(CDCl3) d: 0.10 (3H, s, SiMe), 0.11 (3H, s, SiMe), 0.91 (9H, s, tBu), 1.39
(3H, s, acetonide-Me), 1.61 (3H, s, acetonide-Me), 1.82 (1H, ddd, Jꢁ13.5,
4.8, 0.9 Hz, H-6A), 2.27 (1H, dd, Jꢁ13.5, 11.0 Hz, H-6B), 3.48 (3H, s,
–OMe), 3.69 (1H, d, Jꢁ7.3 Hz, H-2), 3.81 (3H, s, COOMe), 4.17 (1H, dd,
Jꢁ7.3, 5.0 Hz, H-3), 4.26 (1H, ddd, Jꢁ5.0, 3.9, 0.9 Hz, H-4), 4.35 (1H, ddd,
Jꢁ11.0, 4.8, 3.9 Hz, H-5); 13C-NMR (CDCl3) d: ꢂ4.72 (q), ꢂ4.61 (q), 18.26
(s), 25.86 (q), 26.11 (q), 28.25 (q), 36.72 (t), 52.89 (q), 59.72 (q), 65.83 (d),
76.78 (s), 76.96 (d), 79.26 (d), 82.46 (d), 109.41 (s), 174.44 (s); HR-MS
Calcd for C18H35O7Si (MꢃHꢃ), 391.2150; Found, 391.2160.
8: Oil; IR (liquid film) nmax 3482 (OH), 1747 (CꢁO) cmꢂ1 1H-NMR
;
(CDCl3) d: 1.34 (3H, s, acetonide-Me), 1.53 (3H, s, acetonide-Me), 2.00
(1H, dd, Jꢁ13.5, 5.2Hz, H-6A), 2.01 (3H, s, CH3CO), 2.25 (1H, dd, Jꢁ13.5,
11.3 Hz, H-6B), 3.69 (3H, s, COOMe), 4.22 (1H, dd, Jꢁ7.7, 4.9 Hz, H-3),
4.26 (1H, ddd, Jꢁ11.3, 5.2, 4.4 Hz, H-5), 4.40 (1H, dd, Jꢁ4.9, 4.4 Hz, H-4),
5.20 (1H, d, Jꢁ7.7 Hz, H-2); 13C-NMR (CDCl3) d: 20.72 (q), 26.28 (q),
27.69 (q), 35.83 (t), 58.30 (q), 64.69 (d), 74.63 (d), 75.54 (s), 76.05 (d),
76.78 (d), 109.95 (s), 169.51 (s), 173.10 (s); HR-MS Calcd for C13H20O8
(Mꢃ), 304.1160; Found, 304.1158.
Methyl (1S*,2R*,3S*,4R*,5S*)-5-O-tert-Butyldimethylsilyl-3,4-O-iso-
propylidene-1,2-O-dimethyl-1,2,3,4,5-pentahydroxycyclohexanecarboxy-
late 4d Oil; IR (liquid film) nmax 1740 (CꢁO) cmꢂ1; 1H-NMR (CDCl3) d:
0.11 (3H, s, SiMe), 0.13 (3H, s, SiMe), 0.92 (9H, s, tBu), 1.38 (3H, s, ace-
tonide-Me), 1.61 (3H, s, acetonide-Me), 2.09 (1H, ddd, Jꢁ14.2, 5.0, 1.1 Hz,
H-6A), 2.28 (1H, dd, Jꢁ14.2, 11.7 Hz, H-6B), 3.43 (3H, s, –OMe), 3.49 (3H,
s, –OMe), 3.67 (1H, d, Jꢁ7.8 Hz, H-2), 3.78 (3H, s, COOMe), 4.12 (1H,
ddd, Jꢁ11.7, 5.0, 4.1 Hz, H-5), 4.22 (1H, dd, Jꢁ8.0, 4.8 Hz, H-3), 4.27 (1H,
ddd, Jꢁ4.8, 4.1, 1.0 Hz, H-4); 13C-NMR (CDCl3) d: ꢂ4.66 (q), ꢂ4.53 (q),
18.26 (s), 25.85 (q), 26.22 (q), 28.48 (q), 33.29 (t), 52.21 (q), 53.17 (q),
60.74 (q), 65.93 (d), 76.88 (d), 76.99 (d), 79.19(d), 82.24 (s), 83.83 (d),
109.34 (s), 171.92 (s); HR-MS Calcd for C19H37O7Si (MꢃHꢃ), 405.2307;
Found, 405.2308.
Methyl
(1S*,2R*,3R*,4R*)-1-O-Acetyl-5-oxo-3,4-O-isopropylidene-
1,2,3,4-tetrahydroxycyclohexanecarboxylate 9 To a suspension of Dess-
Martin periodinane (423.3 mg) in 5 ml of CH2Cl2, 8 (144.8 mg) in 1 ml of
CH2Cl2 was added at room temperature, after stirring for 1 h. After diluting
with t-butyl methyl ether, the reaction mixture was treated with aqueous
Na2S2O3 and aqueous NaHCO3. The organic layer was washed with brine,
dried over MgSO4, filtered, and the solvent was removed under reduced pres-
sure to give a crude residue, which was purified with silica gel column chro-
matography (eluent, 1% MeOH–CH2Cl2) to afford 9 (121.2 mg, 84%).
9: Oil; IR (liquid film) nmax 3425 (OH), 1762 (CꢁO), 1732 (CꢁO) cmꢂ1
;
1H-NMR (CDCl3) d: 1.35 (3H, s, acetonide-Me), 1.50 (3H, s, acetonide-Me),
2.08 (3H, s, CH3CO), 2.65 (1H, d, Jꢁ17.3 Hz, H-6A), 3.11 (1H, d,
Jꢁ17.3 Hz, H-6B), 3.75 (3H, s, COOMe), 4.58 (2H, m, H-2, H-4), 5.41 (1H,
m, H-2); 13C-NMR (CDCl3) d: 20.71 (q), 25.69 (q), 27.21 (q), 45.18 (t),
53.68 (q), 74.63 (d), 76.01 (s), 77.58 (dꢄ2), 111.47 (s), 169.01 (s), 171.50
(s), 201.49 (s); HR-MS Calcd for C13H17O8 (MꢂHꢃ), 301.0922; Found,
301.0941.
(1S*,3S*,4R*,5S*,6S*)-6-O-Acetyl-4,5-O-isopropylidene-1,4,5,6-pen-
tahydroxycyclohexane-1,3-carbolactone 7a Colorless crystals (CH2Cl2);
mp 173—176 °C; IR (KBr) nmax 3425 (OH), 1799 (CꢁO), 1738 (CꢁO)
cmꢂ1 1H-NMR (CDCl3) d: 1.32 (3H, s, acetonide-Me), 1.57 (3H, s, ace-
;
tonide-Me), 2.04 (1H, d, Jꢁ12.6 Hz, H-2A), 2.20 (3H, s, Ac), 2.67 (1H, dd,
Jꢁ12.6, 6.6 Hz, H-2B), 4.24 (1H, dd, Jꢁ5.8, 2.7 Hz, H-4), 4.61 (1H, ddd,
Jꢁ6.6, 2.7, 1.1 Hz, H-3), 4.89 (1H, ddd, Jꢁ5.8, 5.5, 1.1 Hz, H-5), 5.08 (1H,
d, Jꢁ5.5 Hz, H-6); 13C-NMR (CDCl3) d: 20.73 (q), 25.10 (q), 25.45 (q),
36.92 (t), 71.58 (s), 71.83 (d), 72.38 (d), 75.45 (d), 75.53 (d), 111.54 (s),
174.77 (s); CI-MS m/z 273 (MꢃHꢃ); HR-MS Calcd for C12H18O6
(MꢂCH3ꢃ), 258.1102; Found, 258.1103.
Methyl
(4R*,5R*,6S*)-6-O-Acetyl-4,5-O-isopropylidene-4,5,6-trihy-
droxy-3-oxo-1-cyclohexene-1-carboxylate 10 To a CH2Cl2 solution (2 ml)
of 9 (400.8 mg), pyridine (0.5 ml) and (CF3CO)2O (0.2 ml) were added at
ꢂ10 °C, and after stirring for 30 min the reaction mixture was treated with
saturated aqueous NaHCO3, then extracted with CH2Cl2. The organic layer
was dried over MgSO4, filtered, and the solvent was removed under reduced
pressure to give a crude residue, which was purified with silica gel column
chromatography (eluent, 1% MeOH–CH2Cl2) to afford 10 (270.2 mg, 72%).
10: Oil; IR (liquid film) nmax 1751 (CꢁO), 1731 (CꢁO), 1699 (CꢁO),
(1S*,3S*,4R*,5S*,6S*)-1,6-O-Diacetyl-4,5-O-isopropylidene-1,4,5,6-
tetrahydroxycyclohexane-1,3-carbolactone
7b Colorless
crystals
(CH2Cl2); mp 45—48 °C; IR (KBr) nmax 1816 (CꢁO), 1742 (CꢁO) cmꢂ1
;
1H-NMR (CDCl3) d: 1.33 (3H, s, acetonide-Me), 1.58 (3H, s, acetonide-Me),
2.13 (3H, s, CH3CO), 2.15 (1H, d, Jꢁ12.4 Hz, H-2A), 2.20 (3H, s, CH3CO),
3.22 (1H, dd, Jꢁ12.4, 7.1 Hz, H-2B), 4.23 (1H, dd, Jꢁ5.8, 2.5 Hz, H-4), 4.64
(1H, ddd, Jꢁ7.1, 2.5, 1.4 Hz, H-3), 4.84 (1H, td, Jꢁ5.8, 1.4Hz, H-5), 5.58
(1H, d, Jꢁ5.8 Hz, H-6); 13C-NMR (CDCl3) d: 20.82 (q), 21.22 (q), 25.20 (q),
25.57 (q), 34.19 (t), 68.04 (d), 72.54 (d), 75.00 (d), 75.36 (d), 76.11 (s),
111.56 (s), 168.55 (s), 169.01 (s), 170.25 (s); HR-MS Calcd for C14H19O8
(MꢃHꢃ), 315.1078; Found, 315.1072.
1640 (CꢁC) cmꢂ1 1H-NMR (CDCl3) d: 1.32 (3H, s, acetonide-Me), 1.40
;
(3H, s, acetonide-Me), 2.10 (3H, s, CH3CO), 3.88 (3H, s, COOMe), 4.45
(1H, d, Jꢁ5.4 Hz, H-4), 4.57 (1H, dd, Jꢁ5.4, 2.1 Hz, H-5), 6.11 (1H, dd,
Jꢁ2.1, 1.9 Hz, H-2), 6.97 (1H, d, Jꢁ1.9 Hz, H-6); 13C-NMR (CDCl3) d:
20.74 (q), 25.75 (q), 27.19 (q), 53.07 (q), 63.96 (d), 73.76 (d), 75.32 (d),
110.60 (s), 134.14 (d), 140.86 (s), 164.57 (s), 169.04 (s), 195.45 (s); HR-MS
Calcd for C13H16O7 (MꢃHꢃ), 285.0973; Found, 285.0975.
Methyl (3S*,4S*,5R*,6S*)-6-O-Acetyl-4,5-O-isopropylidene-3,4,5,6-
tetrahydroxy-1-cyclohexene-1-carboxylate 11 To a suspension of NaBH4
(90 mg) in 7 ml of MeOH, 10 (692.5 mg) in 3 ml of MeOH was added drop-
wise at ꢂ10 °C. After stirring for 1 h, the reaction mixture was treated with
saturated aqueous NH4Cl, then extracted with CH2Cl2. The organic layer was
dried over MgSO4, filtered, and the solvent was removed under reduced pres-
sure to give a crude residue, which was purified with silica gel column chro-
matography (eluent, 1% MeOH–CH2Cl2) to afford 11 (428.1 mg, 61%).
11: Oil; IR (liquid film) nmax 3475 (OH), 1741 (CꢁO), 1723 (CꢁO),
(1S*,3S*,4R*,5S*,6S*)-4,5-O-Isopropylidene-6-O-methyl-1,4,5,6-
tetrahydroxycyclohexane-1,3-carbolactone
7c Colorless
crystals
(CH2Cl2); mp 65—67 °C; IR (KBr) nmax 3430 (OH), 1784 (CꢁO) cmꢂ1; 1H-
NMR (CDCl3) d: 1.38 (3H, s, acetonide-Me), 1.58 (3H, s, acetonide-Me),
1.59 (1H, d, Jꢁ12.4 Hz, H-2A), 2.78 (1H, dd, Jꢁ12.4, 6.8 Hz, H-2B), 2.85
(1H, d, Jꢁ8.0 Hz, –OH), 3.45 (3H, s, MeO–), 4.12 (1H, dd, Jꢁ8.0, 5.8 Hz,
H-6), 4.23 (1H, dd, Jꢁ5.8, 2.7 Hz, H-4), 4.59 (1H, br dd, Jꢁ6.8, 2.7 Hz, H-
3), 4.78 (1H, br t, Jꢁ5.8 Hz, H-5) ; 13C-NMR (CDCl3) d: 24.98 (q), 25.63
(q), 31.55 (t), 52.55 (q), 70.10 (d), 74.17 (d), 74.69 (d), 75.41 (d), 79.03 (s),
111.44 (s), 171.52 (s); HR-MS Calcd for C10H14O6 (Mꢃ), 244.0946; Found,
244.0946.
1
1649 (CꢁC) cmꢂ1 ; H-NMR (CDCl3) d: 1.32 (3H, s, acetonide-Me), 1.34
(3H, s, acetonide-Me), 2.01 (3H, s, CH3CO), 3.80 (3H, s, COOMe), 4.45
(1H, m), 4.47 (1H, dd, Jꢁ7.1, 2.2 Hz), 4.70 (1H, ddd, Jꢁ6.3, 4.7, 1.3 Hz),
5.81 (1H, br t, Jꢁ1.3 Hz, H-6), 7.16 (1H, m, H-2); 13C-NMR (CDCl3) d:
20.79 (q), 24.37 (q), 25.95 (q), 52.22 (q), 65.30 (d), 66.72 (d), 74.68 (d),
75.27 (d), 109.52 (s), 128.22 (s), 148.47 (d), 164.75 (s), 165.34 (s); CI-MS
m/z 287(MꢃHꢃ); HR-MS Calcd for C12H15O7 (MꢂCH3ꢃ), 271.0816;
Found, 271.0815.
Methyl (3S*,4R*,5R*,6S*)-6-O-Acetly-3-O-tert-butyldimethylsilyl-4,5-
O-isopropylidene-3,4,5,6-tetrahydroxy-1-cyclohexene-1-carboxylate 12
To a CH2Cl2 solution (5 ml) of 2 (209.8 mg), TBDMSCl (120.0 mg) and imi-
dazole (100.0 mg) were added at room temperature, and after stirring
overnight the reaction mixture was treated with saturated aqueous NaHCO3,
then extracted with CH2Cl2. The organic layer was dried over MgSO4, fil-
tered, and the solvent was removed under reduced pressure to give a crude
residue, which was purified with silica gel column chromatography (eluent,
1% MeOH–CH2Cl2) to give 12 (83.1 mg, 28%).
(1S*,3S*,4R*,5S*,6S*)-1,6-O-Dimethyl-4,5-O-isopropylidene-1,4,5,6-
tetrahydroxylcyclohexane-1,3-carbolactone
7d Colorless
crystals
(CH2Cl2); mp 130—133 °C; IR (KBr) nmax 1785 (CꢁO) cmꢂ1
;
1H-NMR
(CDCl3) d: 1.38 (3H, s, acetonide-Me), 1.59 (3H, s, acetonide-Me), 1.62
(1H, d, Jꢁ12.4 Hz, H-2A), 2.79 (1H, dd, Jꢁ12.4, 6.9 Hz, H-2B), 3.43 (3H, s,
OMe), 3.64 (3H, s, OMe), 3.77 (1H, d, Jꢁ5.5 Hz, H-6), 4.18 (1H, dd, Jꢁ5.5,
2.5Hz, H-4), 4.53 (1H, ddd, Jꢁ6.9, 2.5, 1.1 Hz, H-3), 4.83 (1H, td, Jꢁ5.5,
1.1 Hz, H-5); 13C-NMR (CDCl3) d: 25.21 (q), 25.60 (q), 32.28 (t), 52.49 (q),
59.60 (q), 73.08 (d), 74.41 (s), 75.50 (d), 78.53 (d), 79.22 (d), 111.16 (s),
175.90 (s); CI-MS m/z 257(MꢃHꢃ); HR-MS Calcd for C11H16O6 (MꢃHꢃ),
257.0660: Found, 257.0667.
Methyl
(1S*,2R*,3S*,4S*,5S*)-2-O-Acetyl-3,4-O-isopropylidene-
To THF solution
1,2,3,4,5-pentahydroxycyclohexanecarboxylate
8
a
(4 ml) of 4b (1.55 g), tetrabutylammonium fluoride 1 M in THF (4 ml) was
added at room temperature and stirred overnight. The reaction mixture was
treated with saturated aqueous NH4Cl and extracted with EtOAc. The or-
ganic layer was dried over MgSO4, filtered, and the solvent was removed
12: Oil; IR (liquid film) nmax 1747 (CꢁO), 1725 (CꢁO), 1649 (CꢁC)
cmꢂ1; 1H-NMR(CDCl3) d: 0.16 (3H, s, SiMe), 0.17 (3H, s, SiMe), 0.95 (9H,