Triethylamine → (3R,5S)-1-allyloxycarbonyl-5-[1-hydroxy-(imidazo[5,1-b]thiazol-3-yl)methyl]-3-methanesulfonyloxypyrrolidine

Participants

Reaction Steps

Triethylamine (0.165 ml) and 0.080 ml of methanesulfonyl chloride are successively added to 313 mg of crude (3R,5S)-1-allyloxycarbonyl-3-hydroxy-5-[1-hydroxy-1-(imidazo[5,1-b]thiazol-3-yl)methyl]pyrrolidine (stereoisomer B) in 8.5 ml of THF in an argon atmosphere at −14° C., and the mixture is stirred in this state for 40 min. Further, 0.008 ml of methanesulfonyl chloride is added thereto, and the mixture is stirred for 20 min. A 5% aqueous sodium hydrogencarbonate solution (20 ml) is added thereto, and the mixture is extracted wit 50 ml of ethyl acetate. The organic layer is dried over magnesium sulfate and filtered. The solvent is removed by evaporation under reduced pressure to give 355 mg of crude (3R,5S)-1-allyloxycarbonyl-5-[1-hydroxy-(imidazo[5,1-b]thiazol-3-yl)methyl]-3-methanesulfonyloxypyrrolidine (stereoisomer B) as a slight yellow amorphous material.

Provenance & Evidence