title: 4,4,6a,6b,11,12,14b-Heptamethyl-16-oxo-1,2,3,4,4a,5,6,6a,6b,7,8,9,10,11,12,12a,14a,14b-octa-deca-hydro-12b,8a-(epoxy-methano)-picen-3-yl acetate.
abstract: The title compound, C32H48O4, which was extracted from the bark of Rhododendron arboreum, consists of five fused rings to which an acetate and seven methyl groups are attached. The A, D and E rings adopt chair conformations, the B ring is in a distorted chair and the C ring is in a half-chair conformation. The five-membered ring formed by the lactone group, which bridges from the A/B to the B/C ring junctions, is an approximate envelope with the C atom of the methyne group as the flap [displacement from the other four atoms = 0.753 (2) Å]. There are no identified directional inter-actions in the crystal structure.
authors: University of Peshawar, Institute of Chemical Sciences, Peshawar 25120, Pakistan.
authors: Mohammad
authors: M
authors: Nisar
authors: Sajid
authors: S
authors: Ali
authors: M Nawaz
authors: MN
authors: Tahir
authors: Bashir
authors: B
authors: Ahmad
authors: Shahid
authors: S
authors: Hameed
references: Acta Crystallogr A. 2008 Jan;64(Pt 1):112-22
references: 18156677
references: Acta Crystallogr D Biol Crystallogr. 2009 Feb;65(Pt 2):148-55
references: 19171970