反应详情

To a stirred, cooled (0° C.) solution of 1-(4-chloro-phenyl)-cyclopropanecarbaldehyde (0.36 g) in tetrahydrofuran (15 ml) was added under an argon atmosphere (R)-4-(benzothiazole-2-sulfonylmethyl)-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (1.0 g) followed by a 1 M solution of LiHMDS in THF (4.8 ml). After 1 h at 0° C. the cooling bath was removed and stirring was continued overnight. The mixture was quenched by the addition of sat. aqueous NH4Cl (15 ml) and H2O (15 ml) and extracted with EtOAc. The aqueous phase was back extracted with EtOAc. The combined organics were washed with brine, dried over MgSO4, filtered and concentrated. The crude product was purified by column chromatography (SiO2; gradient: heptane→heptane/EtOAc 2:1) to give (S)-4-{(Z)-2-[1-(4-chloro-phenyl)-cyclopropyl]-vinyl}-2,2-dimethyl-oxazolidine-3-carboxylic acid tert-butyl ester (0.72 g) as light yellow viscous oil. MS (ISP): 378.3 ([M+H]+))

1. customAfter 1 h at 0° C. the cooling bath was removed
2. customThe mixture was quenched by the addition of sat. aqueous NH4Cl (15 ml) and H2O (15 ml)
3. extractionextracted with EtOAc
4. extractionThe aqueous phase was back extracted with EtOAc
5. washThe combined organics were washed with brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. customThe crude product was purified by column chromatography (SiO2; gradient: heptane→heptane/EtOAc 2:1)