syn-Selectivity in the reaction of 1,3-dipoles with cis-cyclobut-3-ene-1,2-diol
Abstract
Cyclic nitrones, C-phenyl-N-methylnitrone, benzonitrile oxide, and 2,4,6-trimethylbenzonitrile oxide react in benzene with cis-cyclobut-3-ene-1,2-diol to give as the sole or the dominant products the sterically disfavoured syn-adducts.