Some oxidation products of lycoctonine revisited

Abstract

The structure of a chromic acid oxidation product of the norditerpenoid alkaloid lycoctonine (1) was established as hydroxylycoctonal (3) by spectrometric analyses and X-ray crystallography of its reduction product, hydroxylycoctonine (5); the structure of lycoxonine, a chromic acid oxidation product of the lactam, lycoctonam (7), was similarly confirmed as N-ethyl-4,7,8-trihydroxy-1α,6β,14α,16β-tetramethoxy-19-oxoaconitane (8). Reduction of lycoxonine with lithium aluminium hydride gave the 1,14-di-O-methyl ether (12) of the bisnorditerpenoid alkaloid delbine (9).Key words: norditerpenoid, bisnorditerpenoid, alkaloids, lycoctonine, lycoctonam, hydroxylycoctonal, lycoxonine. 1,14-di-O-methyldelbine, semisynthesis.