Studies on stereochemistry of thionuphlutine and neothiobinupharidine methiodides and their products of Hofmann degradation

Abstract

Degradation of tetrahydrothiophene ring in two isomeric Nuphar alkaloids–thionuphlutine and neothiobinupharidine has been observed during methylation under thermodynamic control. The C-S bond has been cleaved and the double bond formed in the products of methylation. The structure and stereochemistry of methiodides and their products of Hofmann degradation have been determined by 13C NMR spectroscopy.