REARRANGEMENT OF SUITABLY CONSTITUTED ARYL, ALKYL, OR VINYL RADICALS BY ACYL OR CYANO GROUP MIGRATION
REARRANGEMENT OF SUITABLY CONSTITUTED ARYL, ALKYL, OR VINYL RADICALS BY ACYL OR CYANO GROUP MIGRATION
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DOI：
10.1021/ja00216a033
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发表时间：
1988-04-13
影响因子：
15
通讯作者：
WESTWOOD, SW
中科院分区：
文献类型：
--
作者：
BECKWITH, ALJ;OSHEA, DM;WESTWOOD, SW
摘要 用氢化三丁基锡处理乙酰乙酸三溴苄酯 (14)，通过涉及芳基自由基 15 中的 1, 4-乙酰基迁移（经由环状中间体 16）的机制得到重排产物 20。类似地，衍生自 21 的基团 22 中的 1, 4-氰基迁移得到重排产物 24。然而，衍生自环状酮酯的自由基（例如 26）给出通过 1, 4-酰基迁移和 H 原子转移随后 1, 2-酰基迁移形成的产物。含有0-酮酯环外环的自由基中心的物质中的1, 2-酰基迁移，例如35-*36，提供了合成环状酮酯的有用途径。给出了酰基或氰基向烷基或乙烯基的1、4或1、5迁移的实例。
Abstract Treatment of obromobenzyl acetoacetate (14) with tributyltin hydride affords the rearranged product 20 by a mechanism involving 1, 4-acetyl migration in the aryl radical 15 via a cyclic intermediate 16. Similarly, 1, 4-cyano migration in the radical 22 derived from 21 affords rearranged product 24. However, radicals, eg, 26, derived from cyclic keto esters giveproducts formed both by 1, 4-acyl migration and by H-atom transfer followed by 1, 2-acyl migration. 1, 2-Acyl migration in species containing a radical center exocyclic to a 0-keto ester ring, eg, 35—* 36, provides a synthetically usefulroute to cyclic-keto esters. Examples of 1, 4 or 1, 5 migration of acyl or cyano groups to alkyl or vinyl radicals are given.