反应详情

Sodium borohydride (450 mg, 11.8 mmol) was added to a stirred suspension of (1R*,5S*,6R*)-8-benzyl-1-phenyl-6-phenylsulphonyl-8-azabicyclo[3.2.1]oct-3-en-2-one (Description 2; 3.5 g, 8.1 mmol) in methanol (40 ml) at +5° C. The reaction mixture was stirred for 1 hour and quenched with saturated NaHCO3 and concentrated in vacuo to removed methanol. The aqueous phase was extracted with ethyl acetate (3×50 ml). The combined organic extracts were dried (Na2SO4) and concentrated to give a 4.4:1 mixture of epimeric alcohols. The diastereoisomers were separated by flash chromatography followed by crystallisation.

1. customquenched with saturated NaHCO3
2. concentrationconcentrated in vacuo
3. customto removed methanol
4. extractionThe aqueous phase was extracted with ethyl acetate (3×50 ml)
5. dry with materialThe combined organic extracts were dried (Na2SO4)
6. concentrationconcentrated
7. customto give
8. customThe diastereoisomers were separated by flash chromatography
9. customfollowed by crystallisation