Features of the intramolecular Hosomi-Sakurai reaction of allylic cyclopentenylsilane containing an enol ether moiety

被引：0

作者：

Gimazetdinov, Airat M. ^{[1
]}

Miftakhov, Mansur S. ^{[1
]}

机构：

[1] Russian Acad Sci UFRC RAS, Ufa Inst Chem UfIC, Ufa Fed Res Ctr, Prospect Oktyabrya 71, Ufa 450054, Russia

来源：

TETRAHEDRON LETTERS | 2023年 / 123卷

关键词：

Hosomi-Sakurai reaction; Enol ether; Allylsilanes; Ion-exchange resins; Lewis acid; Intramolecular cyclization;

D O I：

10.1016/j.tetlet.2023.154576

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

A new intramolecular variant of the Hosomi-Sakurai reaction of 5-(2-methoxyvinyl)-4-((phenylthio) methyl)cyclopent-2-en-1-yl)trimethylsilane is presented, which is a by-process between hydrolysis to aldehyde and acetalization to dimethylacetal. The key steps are the generation of methoxy methylene carbocation from enol ether during acid catalysis and its subsequent attack on the allylsilane moiety with formation of norbornene derivative. In turn, the corresponding aldehyde undergoes Hosomi-Sakurai cyclization by interaction with BF3 & BULL;Et2O in acetonitrile, as well as by reaction with TBAF in THF through various transition states, leading to epimeric alcohols of the same norbornene structure. At the same time, the starting enol ether by treatment with TBAF undergoes exclusively protodesilylation and hydrol-ysis, while with BF3 & BULL;Et2O it gives mixtures of epimeric products of topology both bicyclo[2.2.1]heptane and bicyclo[3.2.0]heptane.& COPY; 2023 Elsevier Ltd. All rights reserved.

引用

页数：4