(R)-3-Methyl-2-[2-(4-{1-[(R)-2-methyl-1-(4-nitro-benzyloxycarbonyl)-allyl]-4-oxo-azetidin-2-yldisulfanyl}-pyrimidin-2-yldisulfanyl)-4-oxo-azetidin-1-yl]-but-3-enoic acid 4-nitro-benzyl ester 在
copper dichloride 作用下,
生成
p-nitrobenzyl 2β-(chloromethyl)-2α-methylpenam-3α-carboxylate