8,10-Dibromo-9-methoxy-11-oxo-1-oxa-2-aza-spiro[5.5]undeca-2,7,9-triene-3-carboxylic acid methyl ester 在
zinc tetrafluoroborate 作用下,
以
二氯甲烷 为溶剂,
以9%的产率得到(6R,11S)-8,10-Dibromo-11-hydroxy-9-methoxy-1-oxa-2-aza-spiro[5.5]undeca-2,7,9-triene-3-carboxylic acid methyl ester