Photochemically induced free-radical cyclisation of iodo acetylenic esters provides low yields of mixtures from which both (E)- and (Z)- iodoalkylidene lactones may be isolated. However, photoisomerisation of (E)-iodolkylidene lactones, which have previously been obtained in good yields by dibenzoyl peroxide induced cyclisation of iodo acetylenic esters, provides (E)/(Z)-mixtures from which the previously
碘乙炔酸酯的光
化学诱导的自由基环化提供了低产率的混合物,从中可以分离出(E)-和(Z)-
碘亚烷基内酯。然而,先前通过过氧化二苯甲酰诱导的
碘炔属酯的环化而以高收率获得的(E)-
碘亚烷基内酯的光异构化提供了(E)/(Z)-混合物,从该混合物可以得到先前不可获得的(Z)-异构体。通过色谱法分离。还报道了IR,UV和NMR光谱数据的收集,所有这些提供了与
碘亚烷基内酯的立体
化学有关的有用信息。还包括三甲基甲
硅烷基
碘亚
甲基内酯的(E)-和(Z)-异构体的晶体结构的比较。