Copper(I)-catalyzed reactions of .beta.,.gamma.-epoxy alcohols with Grignard reagents
Copper(I)-catalyzed reactions of .beta.,.gamma.-epoxy alcohols with Grignard reagents
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铜(I)催化的β,γ-环氧醇与格氏试剂的反应
DOI：
10.1021/jo00170a058
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发表时间：
1983
影响因子：
3.6
通讯作者：
A. Fauq
中科院分区：
文献类型：
--
作者：
M. Tius;A. Fauq
正在进行的合成项目需要合成二醇1。将描述用铜（I）催化的格氏试剂定向裂解空间无偏环氧醇的一般程序。环氧醇的区域特异性开环已经被Kishi等人利用得很好。1二甲基铜酸锂对2（R= CH 3）的攻击在C-2处特异性地发生并且以优异的产率进行。在这种情况下观察到的区域化学偏好似乎是Stericin来源，因为在相同条件下处理2（R=H）导致无差别反应，其中形成等量的1，2-和1，3-二醇。2我们将证明，通过明智地选择反应条件，可以观察到2和相关环氧醇在C-2的区域选择性反应。考察了温度对3与二甲基铜酸锂在乙醚中反应的影响。在-20 ℃下观察到所需意义上的适度区域选择性（表I）.降低温度导致区域选择性增加，同时大大减少了反应
An ongoing synthetic project required the synthesis of diol 1. A general procedure for the directed cleavage of sterically unbiased epoxy alcohols with copper (I)-catalyzed Grignard reagents will be described. The regiospecific ring opening of epoxy alcohols has been used to great advantage by Kishi and others. 1 Attack on 2 (R= CH3) by lithium dimethylcuprate takes place specifically and in excellent yield at C-2. The regiochemicalpreference observed in this case appears to be stericin origin because treatment of 2 (R=H) under identical conditions leads to an indiscriminate reaction in which equal amounts of 1, 2-and 1, 3-diol are formed. 2 We will show that regioselective reactions at C-2 of 2 and related epoxy alcohols can be observed by judicious choice of reaction conditions. The effect of temperature upon the reaction of 3 with lithium dimethylcuprate in ether was examined. Modest regioselectivity in the desired sense was observed at-20 C (Table I). Lowering the temperature led to an increase in regioselectivity while greatly diminishing the reaction