Lewis acid- and Bronsted acid-catalyzed stereoselective rearrangement of epoxides derived from himachalenes: access to new chiral polycyclic structures
作者:Abderrahim El Haib、Ahmed Benharref、Sandra Parrès-Maynadié、Eric Manoury、Martine Urrutigoïty、Maryse Gouygou
DOI:10.1016/j.tetasy.2010.12.013
日期:2011.1
The acid-catalyzedrearrangement of two enantiomerically pure epoxides derived from sesquiterpernic himachalenes, which are the main components of the essential oil of the Atlas cedar, has been studied using various Lewis and Bronsted acids. Several new polycyclic compounds have been obtained with different selectivities depending upon the catalysts used and the reaction conditions, and were fully
作者:A. Auhmani、E. Kossareva、H. El Jamili、M. Réglier、M. Pierrot、A. Benharref
DOI:10.1023/a:1011385605706
日期:——
We report here the reactivity of 6 alpha ,7 alpha -epoxyhimachal-2-ene with dibromocarbene generated in situ by phase-transfer catalysis. The stereochemistry of products resulting from dibromocyclopropanation has been established by X-ray crystallography. Compound 3 is orthorhombic P2(1)2(1)2(1) with a = 7.549 (1), b = 8.432 (1). c = 24.469 (1) Angstrom, V = 1559.8 (5) Angstrom (3), Z = 4 and compound 5 is monoclinic P2(1) with a = 8.779 (1), b = 15.684 (1), c = 12.111 (1) Angstrom, beta = 91.869 (1)degrees, V = 1666.7 (4) Angstrom (3) and Z = 4.
Lassaba, E.; Chekroun, A.; Benharref, A., Bulletin des Societes Chimiques Belges, 1997, vol. 106, # 5, p. 281 - 288
作者:Lassaba, E.、Chekroun, A.、Benharref, A.、Chiaroni, A.、Riche, C.、Lavergne, J. P.
DOI:——
日期:——
Benharref, A.; Chekroun, A.; Lavergne, J. P., Bulletin de la Societe Chimique de France, 1991, # 5, p. 738 - 741
作者:Benharref, A.、Chekroun, A.、Lavergne, J. P.
DOI:——
日期:——
Oxydation et addition des dihalocarbènes sur le β-himachalène
Reaction of beta-himachalene with one equivalent of dihalocarbene, KMnO4 or m-CPBA gives regio- and stereospecifically one product resulting from the attack of the C6-C7 double bond. The molecular Structure Shows that this attack occurs on the a face of this double bond. (C) 2002 Elsevier Science Ltd. All rights reserved.