Absolute configuration of isovouacapenol C.

ABSTRACT: The title compound, C(27)H(34)O(5) {systematic name: (4aR,5R,6R,6aS,7R,11aS,11bR)-4a,6-dihy-droxy-4,4,7,11b-tetra-methyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodeca-hydro-phenanthro[3,2-b]furan-5-yl benzoate}, is a cassane furan-oditerpene, which was isolated from the roots of Caesalpinia pulcherrima. The three cyclo-hexane rings are trans fused: two of these are in chair conformations with the third in a twisted half-chair conformation, whereas the furan ring is almost planar (r.m.s. deviation = 0.003?Å). An intra-molecular C-H?O inter-action generates an S(6) ring. The absolute configurations of the stereogenic centres at positions 4a, 5, 6, 6a, 7, 11a and 11b are R, R, R, S, R, S and R, respectively. In the crystal, mol-ecules are linked into infinite chains along [010] by O-H?O hydrogen bonds. C?O [3.306?(2)-3.347?(2)?Å] short contacts and C-H?? inter-actions also occur.

SUBMITTER: Fun HK 

PROVIDER: S-EPMC3007289 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature