Simple treatment of 4-hydroxy-(E)-2-alkenoic esters with benzenethiol leads to cyclization to give 3-phenylthio-4-alkanolides, which are easily converted into 3-phenylthio-2-alken-4-olides and 2-alken-4-olides (Îα,β-butenolides).
用
苯硫酚对
4-羟基-(E)-2-烯酸酯进行简单处理,就会发生环化反应,生成 3-苯
硫基-4-烯醇内酯,这些内酯很容易转化为 3-苯
硫基-2-烯-4-醇内酯和 2-烯-4-醇内酯(δ,δ²-
丁烯内酯)。