4-{[(4R,5R)-8-Bromo-2,2-dimethyl-7-oxo-4-(4-phenyl-butyl)-1,3-dioxa-spiro[4.4]non-8-en-6-yl]-hydroxy-methyl}-benzoic acid methyl ester 在
吡啶 、
4-二甲氨基吡啶 、
乙酸酐 作用下,
反应 1.5h,
生成 4-[8-bromo-2,2-dimethyl-7-oxo-4(R)-(4-phenyl-butyl)-1,3-dioxaspiro[4.4]-5(S)non-8-en-6-(E)-ylidenemethyl]-benzoic acid methyl ester 、 4-[8-bromo-2,2-dimethyl-7-oxo-4(R)-(4-phenyl-butyl)-1,3-dioxaspiro[4.4]-5(S)non-8-en-6-(Z)-ylidenemethyl]-benzoic acid methyl ester