Keten. Part III. The addition of dimethylketen to quinoline, isoquinoline, and phenanthridine

Abstract

The structures of the adducts of dimethylketen with quinoline, isoquinoline, and phenanthridine, and their derivatives have been investigated. In all cases the adduct is formed by cyclo addition of two molecules of dimethylketen across the CN group of the heterocyclic base, to produce derivatives of 3,4,5,6-tetrahydro-2-isopropylidene-5,5-dimethyl-1,3-oxazin-6-one. The structures of the products of hydrolysis and methanolysis have been examined, and several cases of magnetic non-equivalence of methylene protons and methyl groups in isopropyl and gem-dimethyl groups in these compounds are discussed. Mass-spectral fragmenation patterns of the adducts are described.