Propiolic acids add to alkenes in the presence of N-iodosuccinimide to give iodo acetylenic esters. These, on treatment with dibenzoyl peroxide, undergo cyclisation to yield (E)-iodovinylidene butyrolactones. Subsequent alkylation with lithium dimethylcuprate occurs by replacement of the iodine.
在N-
碘代琥珀
酰亚胺的存在下,
丙酸加成到烯烃中,得到
碘炔基酯。在用过氧化二苯甲酰处理后,将它们环化以产生(E)-
碘亚
乙烯基丁内酯。随后通过
碘取代而与二甲基二甲基
碳酸锂进行烷基化。