2-{5-[(3,4-dimethoxyphenyl)(methoxycarbonyl)methylene]-4-hydroxy-2-oxo-2,5-dihydrofuran-3-yl}-4,5-dimethoxybenzoic acid (-)-menthyl ester 在
三溴化硼 作用下,
以
二氯甲烷 为溶剂,
反应 24.0h,
以69%的产率得到methyl 2-{7,8-dihydroxy-1,5-dioxo-1H,3H,5H-furo[3,4-c]isochromen-3-ylidene}-2-(3,4-dihydroxyphenyl)acetate