3-(2,2-Dimethyl-4,6-dioxo-[1,3]dioxan-5-ylidene)-butyric acid 4-methyl-cyclohexa-1,3-dienylmethyl ester 反应 5.0h,
以48%的产率得到3-{3-[1-Methyl-2-(4-methyl-cyclohexa-1,3-dienylmethoxycarbonyl)-ethylidene]-2,4-dioxo-cyclobutylidene}-butyric acid 4-methyl-cyclohexa-1,3-dienylmethyl ester