18252-44-3Relevant academic research and scientific papers
The role of germacrene D as a precursor in sesquiterpene biosynthesis: Investigations of acid catalyzed, photochemically and thermally induced rearrangements
Buelow, Nils,Koenig, Wilfried A
, p. 141 - 168 (2007/10/03)
Germacrene D is considered as a precursor of many sesquiterpene hydrocarbons. We have investigated the acid catalyzed as well as the photochemically and thermally induced rearrangement processes of germacrene D isolated from several Solidago species, which contain both enantiomers of germacrene D. Enantiomeric mixtures of sesquiterpenes of the cadinane, eudesmane (selinane), oppositane, axane, isodaucane, and bourbonane group as well as isogermacrene D were identified as main products and made available as reference compounds for structure investigations and stereochemical assignments of plant constituents. δ-Amorphene, one of the rearrangement products, was identified as a natural product for the first time. The absolute configuration of γ-amorphene was revised by correlation with the absolute configuration of germacrene D. The mechanisms of the rearrangement reactions are discussed. (C) 2000 Elsevier Science Ltd.
Total syntheses of (±)-α- And (±)-β-copaene and formal total syntheses of (±)-sativene, (±)-cis-sativenediol, and (±)-helminthosporal
Wenkert, Ernest,Bookser, Brett C.,Arrbenius, Thomas S.
, p. 644 - 654 (2007/10/02)
Conversion of the previously reported, carvacrol-based 4(S*)-isopropyl-7(R*)-chlorobicyclo[3.1.1]heptan-6-one and its bromo equivalent into (±)-α- and (±)-β-copaene it described. Model 5-nor-β-copaene was synthesized in the following manner, (a) γ-(trimet
Synthesis of Terpenes Containing the Bicycloheptane Ring System by the Intramolecular Cycloaddition Reaction of Vinylketenes with Alkenes. Preparation of Chrysanthenone, β-Pinene, β-cis-Bergamotene, β-trans-Bergamotene, β-Copaene, and β-Ylangene and Lemnalol
Kulkarni, Yashwant S.,Niwa, Maho,Ron, Eyal,Snider, Barry B.
, p. 1568 - 1576 (2007/10/02)
Treatment of geranoyl chloride (20) with triethylamine in toluene at reflux gave the vinylketene 21 which underwent a cycloaddition to give 7,7-dimethyl-2-methylenebicycloheptan-6-one (24) in 43percent yield.Isomerization over Pd gave chrysanthenone (6) in quantitative yield.Wolf-Kischner reduction gave β-pinene (5) in 70percent yield.A similar sequence of reactions starting from (Z,E)- and (E,E)-farnesoyl chloride gave ketones 51 and 57, which were converted to β-cis-bergamotene (8) and β-trans-bergamotene (9), respectively. β-Copaene (10) and β-ylangene (11) were prepared from 57 by a three-step sequence.Treatment of the imidazole 59 with tri-n-butyltin hydride in toluene at reflux gave a 46percent yield of a 1:1 mixture of 10 and 11.Selenium dioxide oxidation of 11 gave the antitumor agent lemnalol.The mechanisms of the regiospecific ketene generation and the cycloaddition reaction have been explored, and the reactivity of the novel bicycloheptanones has been examined.
SIMPLE SYNTHESES OF (+/-)-β-COPAENE, (+/-)-β-YLANGENE AND LEMNALOL.
Snider, Barry B.,Kulkarni, Yashwant S.
, p. 5675 - 5676 (2007/10/02)
The ketone 1a, which we have prepared from geranylacetone in 38percent yield by a four step sequence, has been converted to β-copaene and β-ylangene by a three step secquence.Oxidation of β-ylangene with SeO2 gives lemnalol in 76percent yield.
