Stereochemistry of the reduction of nicotinic acid when it serves as a precursor of anatabine

Abstract

Anatabine derived from [5,6-¹⁴C, ¹³C, 6-³H]-nicotinic acid (which is a precursor of both rings of the alkaloid) was almost devoid of tritium in its pyridine nucleus, but retained 100% at C-6′; this tritium was in a pro-S position, indicating that nicotinic acid was reduced at C-6 by the introduction of a hydrogen in the pro-R position.