1,3-Dipolar cycloadditions to 5-methoxy-2(5H)-furanone
作者:Erik Keller、Ben de Lange、Minze T. Rispens、Ben L. Feringa
DOI:10.1016/s0040-4020(01)81909-8
日期:1993.1
Various nitrile oxides and nitrones, ethyl diazoacetate and an azomethine ylide were examined in 1,3-dipolarcycloadditions to 5-methoxy-2[5H]-furanone, in particular with respect to regio- and diastereoselectivities. Isoxazoles 13–17 and isoxazolidines 21, 22 and 24 were obtained in high yields with anti-facial selectivities and regioselectivities exceeding 95%. In the case of pyrazoline 26 minor