Crystal structure of 7β-hydroxyroyleanone isolated fromTaxodium ascendens(B.)

Abstract

The title compound, C20H28O4[systematic name: (4bS,8aS,10S)-3,10-dihydroxy-2-isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthrene-1,4-dione], is an abietane-type diterpene, which was isolated fromTaxodium ascendens(B.). The compound crystallizes in the chiral space groupP21, but it was not possible to determine the absolute structure of the molecule in the crystal by resonant scattering. The molecular structure is stabilized by two intramolecular O—H...O hydrogen bonds, enclosingS(5) andS(6) ring motifs. In the crystal, molecules are linked by O—H...O and C—H...O hydrogen bonds, forming chains along the [010] direction. The crystal structure of the 10Rstereoisomer of the title compound, isolated from the roots ofPremna obtusifolia(Verbenaceae), has been reported. It crystallized in the chiral space groupP212121, and the absolute structure was determined as (4bS,8aS,10R), by resonant scattering using CuKα radiation [Razaket al.(2010).Acta Cryst.E66, o1566–o1567].