The transformations of (-)-thujopsene in liquid (HSO3F-SO2FCl) and over solid (TiO2/SO42-) superacids, as well as by the action of peroxy acids, were studied. New tricyclic hydrocarbons were isolated. The experimental results were compared with the data of computer analysis of the most probable transformation pathways using molecular-mechanics and quantum-chemical methods.
The stereochemistry of α-pipitzol (1a) has been established by transformation to cedrene (4) and by single crystal X-ray diffraction of α-pipitzol benzoate (1b). The stereochemistries of the related cedranolides β-pipitzol (2a), α-(1c), β-(2c) and γ-perezol (1d) are assigned from their respective ORD curves.
Three types of photosensitized oxygenations of α-cedrene (CED) were investigated, including: rose bengal( RB)-sensitized photooxygenation of α-cedrene in acetonitrile produced one major stereospecific product (cedr-8- exoen-9α-ol), in which the double bond migrated to an adjacent position, this result demonstrated the singlet oxygen process; 9,10-dicyanoanthrathene (DCA) sensitized photooxygenation
A Predictably Selective Palladium-Catalyzed Aliphatic C–H Oxygenation
作者:Dmitry P. Lubov、Mikhail V. Shashkov、Andrey A. Nefedov、Konstantin P. Bryliakov
DOI:10.1021/acs.orglett.2c04371
日期:2023.3.10
oxygenation of nonactivated aliphatic C(sp3)–H groups with peroxycarboxylic acids in the presence of palladium tris(pyridylmethyl)amine complex (0.6 mol %) is reported, providing the corresponding hydroxylated derivatives in up to 94% yields. The oxidation of 3° C–H groups occurs stereospecifically, with the catalyst system demonstrating extremely high sensitivity to electronic effects (adamantane oxidation:
Ruthenium-catalyzed carbon-hydrogen bond activation. Oxyfunctionalization of nonactivated carbon-hydrogen bonds in the cedrane series with ruthenium tetraoxide generated in situ
作者:A. Tenaglia、E. Terranova、B. Waegell
DOI:10.1021/jo00046a040
日期:1992.9
Wojnarowski,W.; Ourisson,G., Bulletin de la Societe Chimique de France, 1967, p. 219 - 223