title: Crystal structure of (1S,3R,8R,9S,10R)-10-bromo-methyl-2,2-di-chloro-9,10-ep-oxy-3,7,7-tri-methyl-tri-cyclo-[6.4.0.0(1,3)]dodeca-ne.
abstract: The title compound, C16H23BrCl2O, was synthesized in three steps 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 is built up from two fused six- and seven-membered rings, each linked to a three-membered ring. The six-membered ring has a screw-boat conformation, whereas the seven-membered ring displays a twist-boat conformation. The absolute structure was established unambiguously from anomalous dispersion effects.
authors.affiliation: Laboratoire de Chimie des Substances Naturelles, Unité Associé au CNRST (URAC16), Faculté des Sciences Semlalia, BP 2390 Bd My Abdellah, 40000 Marrakech, Morocco.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Benharref
authors.affiliation: Laboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Université Mohammed V, Avenue Ibn Battouta, BP 1014, Rabat, Morocco.
authors.forename: Lahcen
authors.initials: L
authors.lastname: El Ammari
authors.affiliation: Laboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Université Mohammed V, Avenue Ibn Battouta, BP 1014, Rabat, Morocco.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Saadi
authors.affiliation: Laboratoire de Chimie des Substances Naturelles, Unité Associé au CNRST (URAC16), Faculté des Sciences Semlalia, BP 2390 Bd My Abdellah, 40000 Marrakech, Morocco.
authors.forename: Moha
authors.initials: M
authors.lastname: Berraho
keywords: crystal structure; β-himachalene derivative; π–π inter­actions