Hydrochloric Acid → (3S,4S)-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-[(1R)-1-[(methylthio)thiocarbonyl}ethyl]-2-oxoazetidine

Participants

Reaction Conditions

Reaction Steps

To a suspension of anhydrous zinc chloride (45.3 g) in acetonitrile (450 ml) cooled to 0° C. was added triethylamine (101 g). After stirring for 30 minutes at 0° C., the solution was cooled to -35° C. and a mixture of methyl dithiopropionate (20.0 g) and (3R,4R)-4-acetoxy-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]-2-oxoazetidine (23.9 g) in acetonitrile (90 ml) was added thereto. The reaction mixture was stirred at -20° C. for 2 hours, warmed to 0° C., and additionally stirred for 30 minutes at 0° C. The mixture was poured into a stirred mixture of dichloromethane (800 ml) and 1N hydrochloric acid (1000 ml). The organic layer was separated, washed with water, aqueous sodium bicarbonate solution and brine, and dried. The solution was concentrated under reduced pressure and the solid residue was washed with n-hexane to afford (3S,4S)-3-[(1R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-[(1R)-1-{(methylthio)thiocarbonyl}ethyl]-2-oxoazetidine (20.1 g) as a yellow crystal.

Provenance & Evidence