反应详情

To a solution of 1 g (3.6 mmol) of diazo-acetic acid 4-(4-methoxy-benzyloxy)-but-2-enyl ester in 50 ml dichloromethane under reflux were added within 8 hrs of 25 mg (0.03 mmol) of Rh2 (5S-MEPY)4 (Doyle dirhodium catalyst from Acros, CAS: 132435-65-5) dissolved in 100 ml of dichloromethane. Refluxing for another 20 hrs, evaporation of the solvent and chromatography on silica gel with heptane/AcOEt gave 850 mg (96%, >92% ee) of (1R,5S, 6S) 6-(4-methoxy-benzyloxymethyl)-3-oxa-bicyclo[3.1.0]hexan-2-one. Colorless oil. MS: 247 (M−H)−.

1. temperatureRefluxing for another 20 hrs
2. customevaporation of the solvent and chromatography on silica gel with heptane/AcOEt