960化工网
Construction of cyclopenta[b]pyran-2-ones via chemoselective (3 + 2) cycloaddition between 2-pyrones and vinyl cyclopropanes†
Xuefeng Liang,Weijian Ye,Waygen Thor,Lantian Sun,Bo Wang,Shuzhong He,Yuen-Kit Cheng
Organic Chemistry Frontiers Pub Date : 02/19/2020 00:00:00 , DOI:10.1039/D0QO00049C
Abstract

A method for synthesising cyclopenta[b]pyran-2-ones through direct (3 + 2) cycloaddition between 2-pyrones and vinyl cyclopropanes is described. In the presence of Pd2(dba)3/dppe in toluene, a series of 2-pyrones undergo chemoselective (3 + 2) cycloaddition with vinyl cyclopropanes and afford cyclopenta[b]pyran-2-ones in high yields (78–96%). The trans/cis ratio of the cycloadducts has been optimised up to 10 : 1. The proposed mechanism of this cycloaddition has been rationalised by computational studies.

Graphical abstract: Construction of cyclopenta[b]pyran-2-ones via chemoselective (3 + 2) cycloaddition between 2-pyrones and vinyl cyclopropanes
平台客服
平台客服
平台在线客服