Synthesis of 1,3-Difunctionalized Cyclopentenes and 1,3,5-Trifunctionalized Cyclohexanes by Silicon-Induced Domino Reactions
作者:Frank Tries、Ernst Schaumann
DOI:10.1002/ejoc.200390160
日期:2003.3
domino process based on a 1,4-C⇄O shift of a silyl group (4 ⇄ 3) and a Michael-induced ring-closure reaction (3 ⇄ 2) is investigated. Specifically, attack of carbanions 5 on vinyloxiranes 6 usually occurs on the oxirane unit to give the desired silyl shift. When starting from vinyloxiranes 6a and 6b, however, the reaction stops at this stage to give silyl ethers 7. Sulfur (6c) or silicon activation (6d−f)
研究了一种基于甲硅烷基 (4 ⇄ 3) 的 1,4-C⇄O 位移和迈克尔诱导的闭环反应 (3 ⇄ 2) 的新型多米诺过程。具体而言,碳负离子 5 对乙烯基环氧乙烷 6 的攻击通常发生在环氧乙烷单元上以产生所需的甲硅烷基位移。然而,当从乙烯基环氧乙烷 6a 和 6b 开始时,反应在此阶段停止以产生甲硅烷基醚 7。C=C 单元的硫 (6c) 或硅活化 (6d-f) 需要产生环戊烯 1a-d。类似地,碳负离子 5a 和烯丙环氧乙烷 15 产生环化产物 19-22,特别是如果闭环步骤由硅取代支持。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)