Terpenoids. Part II. Some ring D derivatives of 13β-kaurane

Abstract

Metal hydride reduction of 13β-kaur-16-en-15-one afforded the 1,4-reduction product, (16R)-13β-kauran-l5β-ol but none of the expected 1,2-reduction product, 13β-kaur-16-en-15β-ol; in concentrated solution, a dimer (19) was a minor product. Treatment of 13β-kaur-16-en-15α-ol with aqueous acid in methanol yielded a dimeric ether (20) in addition to 17-hydroxy- and 17-methoxy-13β-kaur-15-ene. The four isomers of 13β-kauran-15-ol were prepared; their m.p.s and optical rotations differed from those reported previously.

A previously noted division of Cryptomeria japonica into producers of ent-kaurene or 13β-kaurene has been confirmed for fifteen additional varieties.