Studies on Intramolecular Alkylation of an α-Sulfinyl Vinylic Carbanion: a Novel Route to Chiral 1-Cycloalkenyl Sulfoxides
作者:N Maezaki
DOI:10.1016/s0040-4020(00)00713-4
日期:2000.9.29
investigated. Upon treatment with LDA in THF at −78°C, α-sulfinyl carbanion generated from vinylic sulfoxides cyclized at the α-sulfinyl position to give 1-cycloalkenyl sulfoxides with a five- to seven-membered ring. Although iodide or bromide is normally a good leaving group, chloride affords better results than the corresponding iodide and bromide when the reaction takes place at the benzylic position. The cyclization
研究了各种β-(ω-卤代烷基)取代的乙烯基亚砜的分子内烷基化。在-78℃下用LDA在THF中处理后,由乙烯基亚砜产生的α-亚磺酰基碳负离子在α-亚磺酰基位置环化,得到具有五至七元环的1-环烯基亚砜。尽管碘化物或溴化物通常是良好的离去基团,但当反应在苄基位置发生时,氯化物比相应的碘化物和溴化物提供更好的结果。即使次要碘化物以中等收率进行环化反应。不仅是(E)异构体,而且(Z异构体通过烯烃几何结构的快速反转而环化。在异构化过程中未观察到光学纯度的损失。以良好至中等的产率合成了包括稠环和多加氧环的各种1-环烯基亚砜。