Oukhrib Abdelouahd, Benharref Ahmed, Saadi Mohamed, Berraho Moha, El Ammari Lahcen
Laboratoire de Chimie Biomoléculaire, Substances Naturelles et Réactivité "Unité Associée au CNRST (URAC16)", Faculté des Sciences Semlalia, BP 2390, Bd My Abdellah, 40000 Marrakech, Morocco.
Acta Crystallogr Sect E Struct Rep Online. 2013 Mar 9;69(Pt 4):o521-2. doi: 10.1107/S1600536813006077. Print 2013 Apr 1.
The title compound, C16H24Br2O, was synthesized from β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzocyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus atlantica). The mol-ecule contains fused six- and seven-membered rings, each linked to a three-membered ring. The six-membered ring has a half-chair conformation, while the seven-membered ring displays a chair conformation. The dihedral angle between the mean planes through the six- and seven-membered rings is 39.55 (12)°. The two three-membered rings, linked to the six- and seven-membered rings, are nearly perpendicular to the six-membered ring, making dihedral angles of 78.6 (2) and 80.5 (2)°, respectively. The absolute structure was established unambiguously from anomalous dispersion effects. In the crystal, each mol-ecule is linked to its symmetry-equivalent partner by C-H⋯O hydrogen bonds, forming zigzag chains parallel to [100].
标题化合物C₁₆H₂₄Br₂O由β-喜马拉雅烯（3,5,5,9-四甲基-2,4a,5,6,7,8-六氢-1H-苯并环庚烯）合成，β-喜马拉雅烯是从阿特拉斯雪松（Cedrus atlantica）的精油中分离得到的。该分子包含稠合的六元环和七元环，每个环都与一个三元环相连。六元环具有半椅式构象，而七元环呈现椅式构象。通过六元环和七元环的平均平面之间的二面角为39.55 (12)°。与六元环和七元环相连的两个三元环几乎垂直于六元环，二面角分别为78.6 (2)°和80.5 (2)°。通过反常色散效应明确确定了绝对结构。在晶体中，每个分子通过C-H⋯O氢键与其对称等效的分子相连，形成平行于[100]的锯齿链。
