反应详情

A mixture of the ketone 4 from step 3 (70 mg, 0.13 mmol) and the compound 3 (34 mg, 0.17 mmol) was stirred in titanium isopropoxide (45 mg, 0.16 mmol) for 1.5 h. To the mixture were added ethanol (1.0 mL) and NaCNBH3 (5.4 mg, 8.6 mmol) and the mixture was stirred overnight. The reaction mixture was filtered and washed with EtOAc. The filtrate was washed with H2O and brine, dried with MgSO4 and concentrated. The residue was chromatographed on silica gel eluting with 5% NH3 sat. MeOH in CH2Cl2 to give both diastereomers pure.

1. filtrationThe reaction mixture was filtered
2. washwashed with EtOAc
3. washThe filtrate was washed with H2O and brine
4. dry with materialdried with MgSO4
5. concentrationconcentrated
6. customThe residue was chromatographed on silica gel eluting with 5% NH3 sat. MeOH in CH2Cl2
7. customto give both diastereomers pure