作者:Chunyang Jin、Hollie K. Jacobs、Francisco Cervantes-Lee、Aravamudan S. Gopalan
DOI:10.1016/s0040-4020(02)00338-1
日期:2002.5
prepared from the corresponding hydroxysulfones by phase-transfer alkylation reactions. The sulfonyl carbanions of 2a–e are readily generated upon treatment with LHMDS in THF at −78°C and undergo intramolecular acylation reactions to give a variety of functionalized cyclic ethers 4a–e in good yields. The intramolecular aldol-type reaction of the sulfonyl carbanion of 6a is useful for the preparation of six-membered
γ和δ-羟基砜叔丁酯衍生物2a - e可以通过相转移烷基化反应轻松地由相应的羟基砜制得。在-78°C下用LHMDS在THF中处理时,很容易生成2a - e的磺酰基碳负离子,并进行分子内酰化反应,从而以高收率得到各种官能化的环醚4a - e。6a的磺酰基碳负离子的分子内羟醛型反应可用于制备具有高非对映选择性控制的六元氧杂环系统,并且最好在平衡条件下进行(t放入甲苯中)。这项研究清楚地表明,即使在底物中其他地方存在酸度可比的其他质子,也可能产生α-磺酰基碳负离子并影响其分子内环化。已经研究了这种分子内环化策略的范围,局限性和合成效用。