The stereospecific synthesis of .alpha.-methylene-.gamma.-butyrolactones of trans-1,3-dihydroxycycloalkanes
The stereospecific synthesis of .alpha.-methylene-.gamma.-butyrolactones of trans-1,3-dihydroxycycloalkanes
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反式1，3-二羟基环烷烃的α-亚甲基-γ-丁内酯的立体定向合成
DOI：
10.1021/jo00881a038
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
J. Farina
中科院分区：
文献类型：
--
作者：
J. Marino;J. Farina
已发现1，1-二乙氧基-2-丙烯基铜酸酯与3，4-环氧环烯烃的反应在很大程度上是区域特异性和立体特异性的;来自1，3-环庚烷单环氧化物的1，2开环的产物已转化为环庚烷的反式-羟基-顺式-丁内酯。尽管有多种制备稠合到环烷烃上的α-亚甲基-7-丁内酯的合成方法，缺乏用于构建1，3-二醇的α-亚甲基内酯的区域特异性和立体特异性方法。2我们希望报道一个有效的合成方案，将环状烯丙基环氧化物转化为抗肿瘤天然产物helenalin中的trans-hydroxy-cis-a-methylene-7-butyrolactone体系（1）。在euparotin（2）中发现的相关的顺式-羟基反式-α-亚甲基-7-丁内酯也可能从本文所述的反应中获得。
The reactions of l, l-diethoxy-2-propenyl cuprates with 3, 4-epoxycycloalkenes have been found to be largely regiospecific and stereospecific; the product from 1, 2 opening of 1, 3-cycloheptadiene monoepoxide has been converted to the trans-hydroxy-cis-butyrolactone of cycloheptane.Sir: Despite the plurality of synthetic methods1 for the preparation of a-methylene-7-butyrolactones fused to cycloalkanes, there is a scarcity of regiospecific and stereospecific methods for construction of-methylene lactones of 1, 3-diols. 2 We wish to report an efficient synthetic scheme for the con-version of cyclic allylic epoxides into the trans-hydroxy-cis-a-methylene-7-butyrolactone system found in the antitumor natural product, helenalin (1). The related cis-hydroxytrans-a-methylene-7-butyrolactone found in euparotin (2) is also potentially accessible from the reactions described herein.