Tributylstannane → (3R,5s)-1-allyloxycarbonyl-3-t-butyldimethylsilyloxy-5-(5-chloroimidazo[5,1-b]thiazol-2-yl)methylpyrrolidine

Participants

Reaction Conditions

Reaction Steps

Tri-n-butyltin hydride (1.8 ml) and 147 mg of 2,2′-azobisisobutyronitrile are added to a solution of 2.520 g of (3R,5S)-1-allyloxycarbonyl-3-t-butyldimethylsilyloxy-5-[1-(5-chloroimidazo[5,1-b]thiazol-2-yl)-1-(methylthiothiocarbonyloxy)methyl]pyrrolidine (a diastereomer mixture) in 22.5 ml of dry toluene, and the mixture is stirred in an argon atmosphere at an external temperature of 80° C. for 90 min. The reaction solution is diluted with 200 ml of ethyl acetate, washed with semi-saturated saline and dried over anhydrous magnesium sulfate. The solvent is removed by evaporation under reduced pressure to give a crude product which is then purified by column chromatography on silica gel (hexane:ethyl acetate=2:1) to give 1.467 g of (3R,5s)-1-allyloxycarbonyl-3-t-butyldimethylsilyloxy-5-(5-chloroimidazo[5,1-b]thiazol-2-yl)methylpyrrolidine as a slightly yellow oil.

Provenance & Evidence