PREPARATION OF MONOSILYL ACETALS FROM ESTERS VIA IBU(2)ALH REDUCTION AND TRAPPING WITH N-(TRIMETHYLSILYL)IMIDAZOLE - ADDITION OF ALLYLTRIMETHYLSILANE TO YIELD HOMOALLYLIC ALCOHOLS OR ETHERS

被引：27

作者：

SAMES, D ^{[1
]}

LIU, YQ ^{[1
]}

DEYOUNG, L ^{[1
]}

POLT, R ^{[1
]}

机构：

[1] UNIV ARIZONA,DEPT CHEM,TUCSON,AZ 85721

来源：

JOURNAL OF ORGANIC CHEMISTRY | 1995年 / 60卷 / 07期

关键词：

D O I：

10.1021/jo00112a039

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Alkyl esters were reduced with iBu(2)AlH or a 1:1 mixture of iBu(2)AlH and iBu(3)Al (iBu(2)AlH . iBu(3)Al or iBu(5)Al(2)H), followed by trapping of the resulting tetrahedral intermediate with TMS-imidazole to produce monosilyl acetals. Reaction of the mixed acetals with allyltrimethylsilane in the presence of Lewis acids (Hosomi-Sakurai reaction) generated homoallylic alcohols or ethers selectively, depending on the substitution of the monosilyl acetal. TMS methoxy acetals (MeO-CH-OTMS) and TMS ethoxy acetals bearing additional complexing groups such as MeO- or Ph(2)C=N- provided alcohols with 1.5:1-9:1 threoselectivity, while simple TMS ethoxy acetals provided only ethyl ethers as products. The monosilyl acetal configuration was easily epimerized or racemized, and the configuration of the Hosomi-Sakurai product was apparently independent of the initial monosilyl acetal reactant configuration.

引用

页码：2153 / 2159

页数：7

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