反应详情

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).

1. filtrationThen filter
2. customthe reaction through diatomaceous earth
3. concentrationconcentrate the filtrate under vacuum (room temperature/15 mmHg)
4. customPurify the residue by column chromatography [silica gel, 55 g, hexane (300 mL) followed by 5% ethyl acetate/hexane (500 mL)]