3-Methyl-butyric acid 12-acetoxymethyl-4,8-dimethyl-5,7,13-trioxo-3,14-dioxa-tricyclo[9.3.0.02,4]tetradec-11-en-10-yl ester 在
silica gel 作用下,
生成 3-Methyl-butyric acid (Z)-6-acetoxymethyl-1,10-dimethyl-5,13-dioxo-4,14-dioxa-tricyclo[9.2.1.0
3,7]tetradeca-2,6,11-trien-8-yl ester