Intramolecular Carbolithiation of 3-Lithioxy-5-alkenyllithiums as a Platform for Cyclopentanols and Cyclopentanones
作者:Ilhyong Ryu、Go-hei Yamamura、Satoshi Minakata、Mitsuo Komatsu、Haruka Kubo、Mitsuhiro Ueda
DOI:10.1055/s-0035-1560170
日期:——
Intramolecular carbolithiation of 3-lithioxy-5-hexenyllithiums was studied. Unlike the case of 5-hexenyllithium, the cyclization of 3-lithioxy-5-hexenyllithium was very sluggish. Acceleration was observed when lithium chloride was added, suggesting that intramolecular lithioxy coordination would hinder the cyclization. Introduction of a silyl or thiophenyl group at the olefin terminus caused smooth
研究了 3-lithioxy-5-hexenyllithiums 的分子内碳化。与 5-己烯基锂的情况不同,3-锂氧基-5-己烯基锂的环化反应非常缓慢。添加氯化锂时观察到加速,表明分子内锂氧基配位会阻碍环化。在烯烃末端引入甲硅烷基或噻吩基团导致顺利环化。所得具有环戊烷骨架的二价阴离子与亲电试剂进行 C-C 键形成反应,得到 3-取代的环戊醇。结合 Swern 氧化,整个方案充当了 3-取代环戊酮的平台。