Potassium ethanethioate → (3S,5S)-3-Acetylthio-1-allyloxycarbonyl-5-[1-hydroxy-1-(imidazo[5,1-b]thiazol-3-yl)methyl]pyrrolidine

Participants

Reaction Conditions

Reaction Steps

Potassium thioacetate (149 mg) is added to a solution of 355 mg of crude (3R,5S)-1-allyloxycarbonyl-5-[1-hydroxy-1-(imidazo[5,1-b]thiazol-3-yl)methyl]-3-methanesulfonyloxypyrrolidine (stereoisomer B) in a mixture of 3 ml of dry DMF and 1.5 ml of dry toluene, and the mixture is stirred in an argon atmosphere at a bath temperature of 80° C. for 12 hr. The mixture is diluted with 100 ml of ethyl acetate and washed twice with 40 ml of a 5% aqueous sodium hydrogencarbonate solution. The organic layer is dried over magnesium sulfate and filtered, and the solvent is removed by evaporation under reduced pressure. The residue is dried under reduced pressure by means of a vacuum pump for 2 hr. The resultant brown oil is successively purified by column chromatography on silica gel (ethyl acetate) and on Sephadex LH-20 (chloroform:methanol=1:1) to give 139.1 mg of the title compound as a slightly red amorphous material.

Provenance & Evidence