Photocycloaddition of chalcones to yield cyclobutyl ditopic cyclophanes
作者:Francesca R Cibin、Nicoletta Di Bello、Giancarlo Doddi、Vincenzo Fares、Paolo Mencarelli、Elio Ullucci
DOI:10.1016/j.tet.2003.10.026
日期:2003.12
The intramolecular photocycloaddition of chalcones to give cyclobutanes has proved to be a fast and convenient method to shrink a cyclophane ring to a tricyclic system, in order to prepare potential ditopic receptors. X-Ray results confirm the previously indicated structure for the cyclobutanes 2a (n=1, m=1), in which the cyclization occurs by a head-to-head syn ring closure. NMR results indicate that the same process occurs for the cyclobutanes 2b (n=2, m=2) and 2c (n=1, m=3). (C) 2003 Elsevier Ltd. All rights reserved.