反应详情

A solution of 438 mg of (3R,5S)-1-allyloxycarbonyl-5-(5-chloroimidazo[5,1-b]thiazol-2-yl)methyl-3-hydroxypyrrolidine and 672 mg of triphenylphosphine in 6.5 ml of anhydrous THF is cooled to −10° C. in an argon atmosphere. Diethyl azodicarboxylate (0.40 ml) is added dropwise to the mixture over a period of 7 min while maintaining the solution at −5° C. or below, and the mixture is stirred in this state for 23 min. Thiobenzoic acid (90%) (0.34 ml) is added dropwise to the mixed solution at −10° C. over a period of 5 min, and the mixture is stirred in this state for additional 25 min. The solvent is removed by evaporation under reduced pressure to give an oil which is then purified by column chromatography on silica gel (hexane:ethyl acetate=1:1) to give 505 mg of the title compound as a bright yellow viscous material.

1. temperaturewhile maintaining the solution at −5° C. or below
2. stirringthe mixture is stirred in this state for additional 25 min
3. customThe solvent is removed by evaporation under reduced pressure
4. customto give an oil which
5. customis then purified by column chromatography on silica gel (hexane:ethyl acetate=1:1)