Novel Fragmentation Reaction of 2-Alkyl- and 2,4-Dialkyl-3-iodo-1-oxocyclohexan-2,4-carbolactones
作者:Seock-Kyu Khim、Mingshi Dai、Xuqing Zhang、Lei Chen、Liping Pettus、Kshitij Thakkar、Arthur G. Schultz
DOI:10.1021/jo0490853
日期:2004.10.1
2-Alkyl- and 2,4-dialkyl-3-iodo-1-oxocyclohexan-2,4-carbolactones undergo lithium hydroxide- and lithium alkoxide-induced fragmentation reactions to provide butenolides, γ-hydroxycyclohexenones, and/or γ-butyrolactones. In general, product distribution is governed by two factors: (1) the nature of nucleophiles and (2) the steric bulkiness of the substituents at C-2 and C-4 of the cyclohexanones. Lithium
2-烷基-和2,4-二烷基-3-碘-1-氧代环己基-2,4-碳内酯经历氢氧化锂和烷氧基锂诱导的裂解反应,从而提供丁烯内酯,γ-羟基环己烯酮和/或γ-丁内酯。通常,产物分布受两个因素控制:(1)亲核试剂的性质和(2)环己酮在C-2和C-4处取代基的空间体积。氢氧化锂诱导的断裂提供丁烯内酯和γ-羟基环己烯酮。相反,在有限的情况下,锂醇盐促进的断裂会导致主要为5取代的γ-丁内酯以及少量的丁烯内酯。由氢氧化锂诱导的裂解产物在很大程度上受环己酮环的C-2和C-4处取代基的空间体积的影响。