反应详情

A solution of DIBAL (1M in DCM, 13.8 mL, 13.8 mmol) was added dropwise over 10 min to a stirred solution of the ester (52) (1.35 g, 4.59 mmol) in THF (25 mL) under nitrogen at −78° C. The reaction mixture was warmed to RT and then re-cooled to −78° C. and a second aliquot of DIBAL (1M in DCM, 4.5 mL, 4.5 mmol) was added. The reaction mixture was allowed to warm to RT, then cooled to 0° C. and water (5 mL) and then MgSO4 were added. The mixture was diluted with DCM and filtered to remove the solids. The filter cake was washed with EtOAc, MeOH and DCM and the combined filtrate and washings were evaporated in vacuo. The residue was purified by flash column chromatography (SiO2, 40 g, 25-50% EtOAc in isohexane, gradient elution) to afford the title compound (53) (0.62 g, 50%): m/z 253 (M+H)+ (ES+).

1. temperaturere-cooled to −78° C.
2. temperatureto warm to RT
3. temperaturecooled to 0° C.
4. filtrationfiltered
5. customto remove the solids
6. washThe filter cake was washed with EtOAc, MeOH and DCM
7. customthe combined filtrate and washings were evaporated in vacuo
8. customThe residue was purified by flash column chromatography (SiO2, 40 g, 25-50% EtOAc in isohexane, gradient elution)