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The crystal structure of a new diterpene lactone—chilobolide A
Author(s) -
YuZhen Han,
QingChuan Yang,
GenPei Li,
YouQi Tang,
JingYu Su
Publication year - 1988
Publication title -
acta chimica sinica english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 0256-7660
DOI - 10.1002/cjoc.19880060211
Subject(s) - chemistry , orthorhombic crystal system , ring (chemistry) , crystal structure , diffractometer , group (periodic table) , diterpene , lactone , stereochemistry , crystallography , molecule , bicyclic molecule , envelope (radar) , telecommunications , radar , organic chemistry , computer science
Chilobolide A, C 22 H 30 O 5 , M.W. = 374,5, orthorhombic, space group P 2,2,2 1 , a = 8.753 (2), b = 8.887 (3), c = 54.247 (14) Å, V = 4220(2) Å 3 , Z = 8, D x = 1.17 g·cm −3 , F(000) = 1616 e at room temperature. The structure was solved by direct methods with diffractometer data measured with Cu K α radiation, and block‐full‐matrix least‐squares refinement converged at R = 0.064 for 1805 observed reflections. Both molecules in an asymmetric unit have similar conformation. The molecular skeleton is bicyclic system, in which an envelope form γ‐lactone ring is cis ‐fused to a cyclotridecadiene ring, the latter ring is in [−+−+−++++−+−−] asymmetric conformation; the methyl groups attached to 4‐C and 13‐C are situated on E ‐type double bond, the acetyl group is in equatorial orientation at 10‐C and the acetoxy group is in axial at 9‐C.