Phenol oxidation and biosynthesis. Part XXIV. Origin of chirality in the erythrinan system and derivation of the lactone rings of α- and β-erythroidine

Abstract

Erysodienone (III) has been resolved, and the laevorotatory (5S)-antipode is shown to be the precursor of the Erythrina alkaloids. Chiral 5,6,8,9-tetrahydro-2,12-dimethoxy-7H-dibenz[d,f]azonine-3,11-diol, derived from resolved erysodienone, is optically unstable at 20 and at 0°. The biosynthetic implications are discussed.

The aromatic Erythrina alkaloids are shown to be specifically incorporated into the lactone erythroidine alkaloids with retention of the 17-hydrogen atom. Cleavage of the aromatic ring in nature is discussed.