Cycloaddition of ketene dimethyl acetal (7) to dimethyl butynedioate (8) followed by electrocyclic ring opening yields diene 10. This can be hydrolyzed readily to the title compound 1.
将烯酮二甲基
缩醛(7)与
丁炔二酸二甲酯(8)进行环加成反应,然后进行电环开环,得到二烯 10。二烯 10 很容易
水解成标题化合物 1。