6-(1-methoxycarbonyl-2-methyl-propenyl)-7-oxo-4-oxa-2,6-diaza-bicyclo[3.2.0]hept-2-ene-3-carboxylic acid benzyl ester 、 、
铝 、 在
magnesium sulfate 、 crude product 作用下,
以
四氢呋喃 为溶剂,
反应 1.5h,
以to yield 4.92 g of methyl α-(3ξ-carbobenzoxy-7-oxo-4-oxa-2,6-diazabicyclo[3.2.0]heptan-6-yl)-α-isopropylideneacetate as crude product in 98.4% yield的产率得到6-(1-methoxycarbonyl-2-methyl-propenyl)-7-oxo-(1
rH,5
cH)-4-oxa-2,6-diaza-bicyclo[3.2.0]heptane-3ξ-carboxylic acid benzyl ester