(2S,2aS,2bS,5aS,6R)-2-((R)-1-Methanesulfonyloxy-ethyl)-2b-methyl-1,4-dioxo-octahydro-3-oxa-6a-aza-cyclobuta[a]pentalene-6-carboxylic acid benzyl ester 在
1,8-二氮杂双环[5.4.0]十一碳-7-烯 作用下,
以
苯 为溶剂,
反应 1.5h,
以90%的产率得到(2aS,2bS,5aS,6R)-2-Eth-(Z)-ylidene-2b-methyl-1,4-dioxo-octahydro-3-oxa-6a-aza-cyclobuta[a]pentalene-6-carboxylic acid benzyl ester