[Si:1]([O:8][C@@H:9]1[CH2:13][CH2:12][C@H:11]([OH:14])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].C(N(CC)CC)C.[C:22](OC=C)(=[O:24])[CH3:23]>COC(C)(C)C>[C:22]([O:14][C@@H:11]1[CH2:12][CH2:13][C@H:9]([O:8][Si:1]([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2])[CH2:10]1)(=[O:24])[CH3:23]Combine (+/-)-cis-3-tert-butyldimethylsilyloxycyclopentanol (2.119 g, 9.8 mmol, prepared in example 29), pancreatin (6.2 g, 3 weight equivalents), triethylamine (0.9 mL, 6.5 mmol) and vinyl acetate (4.3 mL) in tert-butyl methyl ether (12 mL) and stir for 27 hours at room temperature. Then filter the reaction through diatomaceous earth and concentrate the filtrate under vacuum (room temperature/15 mmHg). Purify the residue by column chromatography [silica gel, 55 g, hexane (300 mL) followed by 5% ethyl acetate/hexane (500 mL)] to provide the (1R,3S)-(+)-3-tert-butyldimethylsilyloxycyclopentanyl acetate (1.23 g, 49% yield, 98% ee as determined from gas chromatography with a chiral column) and (1S,3R)-(-)-3-tert-butyldimethylsilyloxycyclopentanol (771 mg, 37% yield, 92% ee as determined from its acetate derivative followed by GC chiral column analysis, see example 30a).
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