反应详情

温度

0 °C

To a solution of [3aR, 4R(1E), 5R, 6aS]-5-benzoyloxy-4-[4-(3-chlorophenoxy)-3-oxo-1-butenyl]-hexahydro-2H-cyclopenta[b]furan-2-one (1; for preparation, see published European Patent Application EP 639563 A2, which is incorporated herein by this reference) (1.02 g, 2.32 mmol) in THF (10 mL) at −23° C. (bath temperature) was added dropwise a solution of (+)-B-chlorodiisopinocampheylborane (available from Aldrich Chemical Co., Milwaukee, Wis.) (1.4 g, 4.4 mmol) in THF (10 mL). The mixture was then warmed to 0° C. (bath temperature) and was quenched after 90 min by the addition of methanol (10 mL). Saturated NH4Cl was added (35 mL), the mixture was extracted with ethyl acetate (3×40 mL), dried (MgSO4), filtered, concentrated, and chromatographed on a 30 cm tall×41 mm diameter silica gel column eluting with 1:1 ethyl acetate:hexane to afford 2 (502 mg, 49%) as well as a mixture of 2 and its epimeric alcohol (254 mg, 23%).

1. customfor preparation
2. customat −23° C.
3. customwas quenched after 90 min by the addition of methanol (10 mL)
4. additionSaturated NH4Cl was added (35 mL)
5. extractionthe mixture was extracted with ethyl acetate (3×40 mL)
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. concentrationconcentrated
9. customchromatographed on a 30 cm tall×41 mm diameter silica gel column
10. washeluting with 1:1 ethyl acetate