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HETEROCYCLES, Vol. 77, No. 2, 2009
Organic phase was separated and the aqueous phase was extracted with CH2Cl2. The combined organic
extracts were dried over Na2SO4 and concentrated. The crude residue was purified by column
chromatography (80% EtOAc in petroleum ether) to afford 22 (220 mg, 74.5%) as a colorless oil. [α]D
–2.9 (c 1.0, MeOH). IR (CHCl3): 3369, 2930, 1454, 1046, 753, 698 cm-1. 1H NMR (CDCl3, 500 MHz) δ:
1.44 (br s, 1H), 1.87 (br s, 1H), 1.96-2.03 (m, 1H), 3.53 (t, J = 7.3 Hz, 1H), 3.62 (br s, 1H), 3.81 (br s,
13
2H), 3.82-3.96 (br s, 4H), 4.44 (d, J = 11.4 Hz, 1H), 4.53 (d, J = 11.4 Hz, 1H), 7.22-7.31 (m, 5H). C
NMR (CDCl3, 125 MHz) δ: 29.4 (t), 43.4 (d), 65.0 (t), 71.6 (t), 77.5 (d), 78.6(d), 79.2 (d), 127.9 (d),
128.5 (d), 137.9 (s). Anal. Calcd for C13H18O4: C, 65.53; H, 7.61. Found: C, 65.37; H, 7.26.
(1R,2S,3R,5R)-3-(Benzyloxy)-5-((tert-butyldimethylsilyloxy)methyl)cyclopentane-1,2-diol (23).
To an ice-cold solution of 22 (500 mg, 2.1 mmol) in CH2Cl2 (12 mL), were added imidazole (420 mg, 6.3
mmol) and TBS-Cl (340 mg, 2.31 mmol). The reaction mixture was stirred for 0.5 h concentrated and
purified by column chromatography (40% EtOAc in petroleum ether) to yield 23 (490 mg, 66%) as
colorless oil. [α]D –18.9 (c 0.8, CHCl3). IR (CHCl3): 3424, 2929, 1255, 1216, 1067, 837, 758, 668 cm-1.
1H NMR (CDCl3, 500 MHz) δ: 0.06 (d, J = 1.9 Hz, 6H), 0.90 (s, 9H), 1.50 (dddd, J = 4.4, 8.8, 13.2, 18.1
Hz, 1H), 1.62 (br s, 1H), 1.9 (dt, J = 7.8, 16.6 Hz, 1H), 2.6 (dq, J = 6.3, 8.8, 15.1Hz, 1H), 2.69–2.71 (d, J
= 5.8, 1H), 3.60 (t, J = 7.83 Hz, 1H), 3.74 (qt, J = 5.4, 9.8 Hz, 1H), 3.85 (br s, 1H), 3.89–3.94 (m, 2H),
4.49 (d, J = 11.7 Hz, 1H), 4.61 (d, J = 11.7 Hz, 1H), 7.30-7.37 (m, 5H). 13C NMR (CDCl3, 125 MHz) δ:
5.4 (q), 18.2 (s), 25.9 (q), 29.4 (t), 43.2 (d), 66.0 (t), 71.4 (t), 77.0 (d), 78.3 (d), 80.5 (d), 127.7 (d), 127.8
(d), 128.5 (d), 137.9 (s). Anal. Calcd for C19H32O4Si: C, 64.73; H, 9.15. Found: C, 64.66; H, 9.12.
(1R,2R,3R,5R)-3-(Benzyloxy)-5-((tert-butyldimethylsilyloxy)methyl)cyclopentane-1,2-diyl diacetate
(24).
To a solution of 23 (400 mg, 1.13 mmol) in pyridine (8 mL), was added acetic anhydride (460 mg, 4.54
o
mmol) at 0 C. The reaction mixture was stirred for 12 h, and concentrated. The residue obtained was
purified by column chromatography (10% EtOAc in petroleum ether) to give 24 (340 mg, 73%) as
colorless oil. [α]D –8.6 (c 1.7, MeOH). IR (CHCl3): 3019, 2929, 1737, 1216, 1108, 838, 758, 668 cm-1. 1H
NMR (CDCl3, 500 MHz) δ: 0.02 (d, J = 1.3 Hz, 6H), 0.87 (s, 9H), 1.73-1.81 (m, 1H), 2.02-2.08 (m, 8H),
3.56-3.76 (m, 2H), 3.96-4.05 (m, 1H), 4.50-4.51 (m, 2H), 5.10 (qt, J = 4.4, 3.8 Hz, 2H), 7.26-7.34 (m,
5H).13C NMR (CDCl3, 125 MHz) δ: 5.53 (q), 5.44 (q), 18.2 (s), 20.9 (q), 21.02 (q), 25.9 (q), 30.8 (t), 42.9
(d), 64.4 (t), 71.9 (t), 78.0 (d), 127.5 (d), 128.4 (d), 138.2 (s), 170.1 (s), 170.4 (s). Anal. Calcd for
C23H36O6Si: C, 63.27; H, 8.31. Found: C, 63.54; H, 8.26.
(1R,2R,3R,5R)-3-(Benzyloxy)-5-(hydroxymethyl)cyclopentane-1,2-diyl diacetate (5).
To a solution of 24 (300 mg) in EtOH (8 mL), 0.8% H2SO4 (catalytic amount) was added stirred at rt for