title: (1S,3R,8R,9S,11R)-2,2-Di-bromo-10,10-di-chloro-3,7,7,11-tetra-methyl-tetra-cyclo-[6.5.0.0(1,3).0(9,11)]trideca-ne.
abstract: The title compound, C17H24Br2Cl2, was synthesized from β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The mol-ecule contains fused six-, seven- and two three-membered rings. The six-membered ring has a half-chair conformation, while the seven-membered ring displays a boat conformation. The absolute structure was unambiguously established from anomalous dispersion effects. The crystal packing exhibits no short inter-molecular contacts.
authors.affiliation: Laboratoire de Chimie Biomoléculaire, Substances Naturelles et Réactivité "Unité Associée au CNRST (URAC16)", Université Cadi Ayyad, Faculté des Sciences Semlalia, BP 2390, Bd My Abdellah, 40000 Marrakech, Morocco.
authors.forename: Najia
authors.initials: N
authors.lastname: Ourhriss
authors.forename: Ahmed
authors.initials: A
authors.lastname: Benharref
authors.forename: Mohamed
authors.initials: M
authors.lastname: Saadi
authors.forename: Moha
authors.initials: M
authors.lastname: Berraho
authors.forename: Lahcen
authors.initials: L
authors.lastname: El Ammari