Carbon Disulfide → (3S, 4R)3-[(R)-1-t-Butyldimethylsilyloxyethyl]-4-[1-methyl-2-p-nitrobenzyloxycarbonylaminoethylthio(thiocarbonyl)]thioazetidin-2-one

Participants

Reaction Steps

168 mg (0.59 mmole) of 1-methyl-2-(p-nitrobenzyloxycarbonylamino)ethanethiol were added to a solution of 12.5 mg (0.57 mmole) of metallic sodium in 4 ml of methanol at -10° C., and then the mixture was stirred for 5 minutes. 45 mg (0.59 mmole) of carbon disulphide were added to the resulting solution at the same temperature, followed by stirring for 10 minutes. Then 154 mg (0.54 mmole) of (3R, 4R)-4-acetoxy-3-[(R)-1-t-butyldimethylsilyloxyethyl]azetidin-2-one were added to the solution at the same temperature. The bath temperature was slowly elevated to 0° C. over a period of about 1 hour. After completion of the reaction, the reaction solution was made slightly acidic by the addition of a drop of acetic acid, diluted with ethyl acetate, washed with a saturated aqueous solution of sodium chloride and dried. After evaporation of the solvent, the resulting residue was subjected to column chromatography through 10 g of silica gel eluted with a 10-15% v/v solution of ethyl acetate in benzene, to give 237 mg (yield 77%) of the desired product as a yellow oil.

Provenance & Evidence