Synthese von funktionalisierten Bi(cyclopropylidenen)
摘要:
In view of the synthesis of attractive triafulvalene precursors 9, a series of bi(cyclopropylidenes) 8 with vinyl-(8a), alkoxycarbonyl (8c -f), hydroxymethyl (8h), as well as protected hydroxymethyl groups (8g, 8i) have been prepared by simple one-pot reactions of the corresponding 1,2-dibromo-cyclopropanes 6 with BuLi/CuCl2 at -95 degrees. First experiments towards a direct low-temperature synthesis of bi(cyclopropylidenes) bearing good leaving groups 9k (X = AcO) and 91 (X = Br) are reported.
Synthese von funktionalisierten Bi(cyclopropylidenen)
摘要:
In view of the synthesis of attractive triafulvalene precursors 9, a series of bi(cyclopropylidenes) 8 with vinyl-(8a), alkoxycarbonyl (8c -f), hydroxymethyl (8h), as well as protected hydroxymethyl groups (8g, 8i) have been prepared by simple one-pot reactions of the corresponding 1,2-dibromo-cyclopropanes 6 with BuLi/CuCl2 at -95 degrees. First experiments towards a direct low-temperature synthesis of bi(cyclopropylidenes) bearing good leaving groups 9k (X = AcO) and 91 (X = Br) are reported.
Intramolecular Trapping of Esters by 1-Lithio-1-bromocyclopropanes
作者:Mark S. Baird、Florian A.M. Huber、Viacheslav V. Tverezovsky、Ivan G. Bolesov
DOI:10.1016/s0040-4020(00)00385-9
日期:2000.6
Reaction of 2-acyloxymethyl-1,1-dibromocyclopropanes with methyllithium at -90 degrees C leads to selective bromine-lithium exchange and intramolecular cyclisation to give a 1-bromo-3-oxabicyclo[3.1.0]hexan-2-ol. (C) 2000 Elsevier Science Ltd. All rights reserved.