Selective lithiation of 2-methyloxazoles. Applications to pivotal bond constructions in the phorboxazole nucleus

被引：62

作者：

Evans, DA ^{[1
]}

Cee, VJ ^{[1
]}

Smith, TE ^{[1
]}

Santiago, KJ ^{[1
]}

机构：

[1] Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA

来源：

ORGANIC LETTERS | 1999年 / 1卷 / 01期

关键词：

D O I：

10.1021/ol990027r

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The lithiation of 2-methyloxazoles with alkyllithium and hindered lithium amide bases generally results in the competitive formation of a mixture of 5-lithio- and 2-(lithiomethyl)oxazole isomers. Herein a synthetically useful lithiation method which allows for the selective formation of 2-(lithiomethyl)oxazole is described. Diethylamine has been found to be a kinetically competent proton source that will mediate the equilibration of the kinetically formed 5-lithiooxazole to its more stable 2-(lithiomethyl)oxazole counterpart. Application of this metalation strategy with lithium diethylamide to two important bond constructions relevant to a projected phorboxazole synthesis is presented.

引用

页码：87 / 90

页数：4

共 32 条

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