The stereochemistry and Hofmann degradation of Lupinine methiodides

Abstract

Optical rotation studies on the epimers (-)-lupinine and (+)-epilupinine and their methiodides lead to the conclusion that while (+)-epilupinine methiodide has the normal trans-ring junction, (-)-lupinine methiodide has a cis-ring junction. Unlike the quaternary salts of cryptopleurine, canadine, and tetrahydropalmatine, neither of the lupinine methiodides could be racemized by refluxing with alkali.