Quinoline alkaloids. Part VIII. The synthesis and nuclear magnetic resonance spectra of (±)-platydesmine, (±)-isobalfourodine, and related compounds

Abstract

In contrast to the oxidative cyclisation of N-methyl-(3-methylbut-2-enyl)quinolones, reaction with peroxylauric acid of the corresponding quinolones lacking the N-methyl group yielded a mixture of furano- and pyrano-derivatives, which can be identified by nuclear magnetic resonance spectroscopy in dimethyl sulphoxide. This led to syntheses of balfourodine, isobalfourodine, and platydesmine, and the constitution of the latter alkaloid was thereby established. Some of the results have been reported briefly.