SYNTHESES AND ABSOLUTE CONFIGURATION ASSIGNMENTS OF MONO-AND DI-SUBSTITUTED CHIRAL QUINOLINE ALKALOIDS OBTAINED BY ASYMMETRIC OXIDATION

Mono- and di-substituted quinoline, 2-quinolone, dihydrofuroquinoline and dihydropyranoquinoline alkaloids have been synthesised with enantiomeric excess values of > 90%, via asymmetric epoxidation, or asymmetric dihydroxylation of the corresponding alkene precursors. The absolute configurations of isobalfourodine, ψ-balfourodine, ψ-isobalfourodine, isobalfourodinium methiodide, balfourolone, hydroxylunidine, orixine, nororixine, isopteleflorine, O-acetylisopteleflorine, 0-methylhydroxylunium methiodide and hydroxylunine have been rigorously determined by a combination of circular dichroism spectroscopy, ozonolysis, and stereochemical correlation. Of these, the absolute configurations of six alkaloids were previously unknown and six were assigned incorrect configurations in the literature.