Structure of ent-15 -hydroxy-kaur-16-en-19-oic acid

Ent-15α-hydroxy-kaur-16-en-19-oic acid, C20H30O3, isolated from the leaves of Coespeletia moritziana, is reported in this work. This compound crystallizes in the monoclinic system, space group C2 and unit cell parameters a=19.7509 (5), b=10.5126 (3), c=8.8020 (3) , β=93.722(2)° and V= 1823.73(9) 3. The structure consists of three six-membered rings, labeled A, B, and C and a five-membered ring, called ring D. Additionally, this compound shows 7 chiral atoms whose configuration, obtained by anomalous dispersion, is represented by R-C4, S-C5, R-C8, S-C9, S-C10, R-C13 and R-C15.