反应详情

Analogously to Example 24, 0.12 ml of thionyl chloride and 0.23 ml of triethylamine in 0.23 ml of absolute tetrahydrofuran are added to a solution of 640 mg of 2-[(3S,4R)-4-(2-p-nitrobenzyloxycarbonylaminoethylthiothiocarbonylthio)-3-methoxy-2-oxoazetidin-1-yl]-2-hydroxyacetic acid p-nitrobenzyl ester in 4.5 ml of absolute tetrahydrofuran. After reacting and working up, 0.54 g of triphenylphosphine is added to the crude 2-[(3S,4R)-4-(2-p-nitrobenzyloxycarbonylaninoethylthiothiocarbonylthio)-3-methoxy-2-oxoazetidin-1-yl]-2-chloroacetic acid p-nitrobenzyl ester, obtained as intermediate, in 1.15 ml of absolute tetrahydrofuran. After working up and chromatography over silica gel, the title compound is obtained.