2H n.m.r. spectroscopy as a probe of the stereochemistry of biosynthetic reactions. The biosynthesis of nicotine

Abstract

The pyrrolidine ring of nicotine is derived from L-ornithine which, in intact Nicotiana tabacum, is decarboxylated with retention of configuration; the resulting putrescine is N-methylated and then oxidised, with loss of the pro-S proton on C-4, to yield N-methyl-1-pyrrolinium ion, which is attacked by the pyridine ring precursor at the 1-si,2-re face to yield (S)-nicotine.