Studies on a Chirality of Orellanine. Spectral Nonequivalence of Atrop-isomers of Tetra-O-methylorellanine and Related Compounds Induced by Chiral Solvating Agents

Abstract

The precise carbon-hydrogen correlations of orellanine tetramethyl ether were established by NMR techniques and the methylated alkaloid, as well as some of its structural analogues, was subjected to 1 H NMR experiments with the use of (R)-(+)-t-butylphenylphosphinothioic acid, BINOL or TADDOL as the chiral solvating agents. It was found that tetramethylorellanine, as well as 3,3'-dimethoxy-2,2'-bipyridine-N,N'-dioxide, and some other model compounds gave, in such conditions, proton spectra being composed of separated patterns, each of which corresponds to the individual enantiomer.