Characterization of the Diastereoisomers of Nicotine-1′-N-Oxide, a Metabolite of Nicotine, and Other Possible Oxidation Products by Nuclear Magnetic Resonance Spectroscopy

Abstract

1. R,S-cis and S,S-trans(methyl/pyridyl) diastereoisomeric mixtures of nicotine-1′-N-oxide and nicotine-1,1′-di-N-oxide, nicotine-1-N-oxide and S-(-)-cotinine were synthesized from S-(-)-nicotine and characterized by descending paper chromatography and n.m.r. spectroscopy.

2. Both nicotine-1,1′-di-N-oxide and nicotine-1-N-oxide predominated as the S,S-trans diastereoisomers; the percentage of R,S-cis nicotine-1,1′-di-N-oxide formed depended on the route of synthesis employed. The possible mechanism of N-oxide formation is discussed.