X = Y - ZH Systems as potential 1,3-dipoles. Part 37 generation of nitrones from oximes. Tandem intramolecular 1,3-azaprotio cyclotransfer - intramolecular 1,3-dipolar cycloaddition reactions. Class 4 processes.

Abstract

Aldoximes and ketoximes containing two alkenyl moieties in different side chains undergo thermal conversion to 5 - and 6 - membered cyclic nitrones, via concerted 1,3 - azaprotio cyclotransfer, followed by stereospecific intramolecular cycloaddition to give tricyclic spiro- and fused- ring systems. An X-ray crystal structure of one such product is reported.