Studies on the syntheses of heterocyclic compounds. Part 678. Photoracemisation and photoepimerisation of the phthalidylisoquinoline alkaloids (–)-α-narcotine and (–)-β-hydrastine

Abstract

Irradiation of (–)-α-narcotine (3) in tetrahydrofuran gave a mixture of racemates of two epimers, (±)-α-narcotine (5) and (±)-β-narcotine (7). Similarly, irradiation of (–)-β-hydrastine (4) afforded (±)-α-hydrastine (8) and (±)-β-hydrastine (6).