Bryophyte constituents; 6: Synthesis of herbertene-derived sesquiterpenes from Herberta adunca

Article abstract of DOI:10.1055/s-1996-4309

Efficient total syntheses are described for the racemic sesquiterpenes herbertenolide (2), α-herbertenol (3) and β-herbertenol (4) from Herberta adunca. ent-Herbertenolide [(+)-2] was prepared from enantiopure (-)-ethyl (1R)-1-methyl-2-oxocyclopentanecarboxylate (9) obtained from ethyl 2-oxocyclopentanecarboxylate (19) via reduction with baker's yeast.