DTBB-catalysed lithiation of 1,7-dihydrodibenzothiepin

被引：17

作者：

Yus, M ^{[1
]}

Foubelo, F ^{[1
]}

机构：

[1] Univ Alicante, Fac Ciencias, Dept Quim Organ, E-03080 Alicante, Spain

来源：

TETRAHEDRON LETTERS | 2001年 / 42卷 / 13期

关键词：

sulfur/lithium exchange; DTBB-catalysed lithiation; functionalised biphenyls;

D O I：

10.1016/S0040-4039(01)00200-3

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Treatment of 1,7-dihydrodibenzothiepin (1) with an excess of lithium powder and a catalytic amount of DTBB (5 mol%) at -78 degreesC for 30 min followed by reaction with a carbonyl compound {' BuCHO, Ph(CH2)(2)CHO, PhCHO, Me2CO, [Me(CH2)(4)](2)CO, (CH2)(5)CO, (CH2)(7)CO, (-)-menthone) at the same temperature led, after hydrolysis with 3N hydrochloric acid, to sulfenyl alcohols 4. When alkoxide 3, which is formed after addition of the first carbonyl compound [Me,CO, (CH,),CO, (-)-menthone], is stirred at room temperature for 30 min, a new lithiation occurred and after addition of a second electrophile [Me2CO, Et2CO, (CH2)(5)CO, ClCO2Et] and final hydrolysis with water, difunctionalised biphenyls 6 are formed. Treatment of the sulfenyl alcohol 4c with 85% phosphoric acid in toluene at reflux for 4 h gave the sulfur-containing eight-membered heterocycle 8c in good yield. (C) 2001 Elsevier Science Ltd. All rights reserved.

引用

页码：2469 / 2472

页数：4