(3S,4R)-3-(tert.-butyl-dimethylsilyloxymethyl)-4-[(3R,S)-3-(tetrazol-1-yl)-butyroylthio]-azetidin-2-one 生成 2-[(3S,4R)-3-(tert.-butyl-dimethylsilyloxymethyl)-4-[(3R,S)-3-(tetrazol-1-yl)-butyroylthio]-2-oxoazetidin-1-yl]-2-hydroxyacetic acid allyl ester