Cyclobutene derivatives from addition of α-halogeno electrophilic olefins to ynamines
作者:J.Ø. Madsen、S.-O. Lawesson
DOI:10.1016/s0040-4020(01)97530-1
日期:1974.1
cycloaddition and subsequent allylic isomerization is formulated on the basis of stereochemical and kinetic data. The halogen substituents of the cyclobutene derivatives are stereospecifically displaced by the OH or the OEt groups in solvolytic reactions, with retention of configuration. Methylenecyclobutene derivatives are obtained from the 3-methylcyclobutenes by elimination of hydrogen halide with
α-氯代和α-溴代丙烯腈,α-氯代和α-溴代丙烯酸酯与二乙基氨基甲基乙炔和二乙基氨基苯基乙炔的反应可高收率生成3型环丁烯衍生物。E-和Z的反应-α-溴丁烯腈以立体定向方式发生。基于立体化学和动力学数据,制定了用于环加成反应和随后的烯丙基异构化反应序列的机理方案。在溶剂分解反应中,环丁烯衍生物的卤素取代基被OH或OEt基立体定向置换,并保持构型。通过用叔丁醇钾消除卤化氢,从3-甲基环丁烯获得亚甲基环丁烯衍生物。环丁烯的烯胺官能团的水解产生相应的环丁酮。通过1 H-和13 C-NMR光谱已经建立了四对顺-反异构体环丁烯的构型。