89576-52-3Relevant academic research and scientific papers
Stereocontrolled Regiospecificity of the Water Loss from trans-Sobrerol Radical Cation upon Electron Ionization
Selva, Antonio,Ferrario, Francesco,Ventura, Paolo,Pellegata, Renato
, p. 523 - 529 (1987)
Water loss from trans-sobrerol upon electron impact ionization selectively involves the tertiary OH group, predominantly occuring by a stereocontrolled H-transfer from C(5) position in a rate-determining step process, as proved by 18O and deuterium labelling.Monomethyl ethers behave accordingly.Ionic structures of the water-loss product or products are investigated by metastable ion and collision activation mass-analysed ion kinetic energy spectroscopy, using model ions generated from some substrates, which are chemically related to trans-sobrerol in condensed phase, i.e. α-pinane epoxide, cis-sobrerol and pinol.A substantial conversion of cis-sobrerol molecular ions to ionized pinol by loss of water has been demonstrated.
Heteropoly acid catalysts in upgrading of biorenewables: Synthesis of para-menthenic fragrance compounds from α-pinene oxide
Ribeiro, Cláudio J.A.,Pereira, Matheus M.,Kozhevnikova, Elena F.,Kozhevnikov, Ivan V.,Gusevskaya, Elena V.,da Silva Rocha, Kelly A.
, p. 166 - 170 (2019/01/04)
The isomerization of α-pinene oxide in the presence of Cs2.5H0.5PW12O40 (CsPW) heteropolysalt as solid acid catalyst is reported. The reactions were performed in various solvents, which allowed to obtain trans-carveol, trans-sobrerol and pinol in 60–80% yield each, which exceed the yields reported so far. The CsPW catalyst could be recovered and reused without loss of its activity and selectivity.
Nanoporous alumino- and borosilicate-mediated Meinwald rearrangement of epoxides
Davies, Thomas E.,Kondrat, Simon A.,Nowicka, Ewa,Kean, Joseline L.,Harris, Christopher M.,Socci, Joseph M.,Apperley, David C.,Taylor, Stuart H.,Graham, Andrew E.
, p. 17 - 24 (2015/09/28)
Nanoporous alumino- and borosilicate materials, produced using an evaporation-induced self-assembly approach (EISA), efficiently catalyse the Meinwald rearrangement of epoxides in dimethyl carbonate (DMC) to produce the corresponding carbonyl compounds in high yield and excellent selectivity.
Phosphotungstic acid as a versatile catalyst for the synthesis of fragrance compounds by α-pinene oxide isomerization: Solvent-induced chemoselectivity
Da Silva Rocha, Kelly A.,Hoehne, Juliana L.,Gusevskaya, Elena V.
body text, p. 6166 - 6172 (2009/06/17)
The remarkable effect of the solvent on the catalytic performance of H 3PW12O40, the strongest heteropoly acid in the Keggin series, allows direction of the transformations of α-pinene oxide (1) to either campholenic aldehyde (2), trans-carveol (3), trans-sobrerol (4a), or pinol (5). Each of these expensive fragrance compounds was obtained in good to excellent yields by using an appropriate solvent. Solvent polarity and basicity strongly affect the reaction pathways: nonpolar nonbasic solvents favor the formation of aldehyde 2; polar basic solvents favor the formation of alcohol 3; whereas in polar weakly basic solvents, the major products are compounds 4a and 5. On the other hand, in 1,4-dioxane, which is a nonpolar basic solvent, both aldehyde 2 and alcohol 3 are formed in comparable amounts. The use of very low catalyst loading (0.005-1 mol%) and the possibility of catalyst recovery and recycling without neutralization are significant advantages of this simple, environmentally benign, and low-cost method. This method represents the first example of the synthesis of isomers from α-pinene oxide, other than campholenic aldehyde, with a selectivity that is sufficient for practical usage.
Reaction of cyclic allylic acetates with aliphatic alcohols in the presence of cerium(III) chloride
Uzarewicz,Dresler
, p. 1921 - 1930 (2007/10/03)
The reactions of selected allylic acetates with methanol, ethanol, n-propyl alcohol, isopropyl alcohol and tert-butyl alcohol in the presence of catalytic amounts of cerium(III) chloride are described. Allylic alkyl ethers, bis-allylic ethers and 1,3-dienes were obtained depending on the structure of the acetates.
The reaction of cyclic allylic alcohols with aliphatic alcohols in the presence of cerium(III) chloride
Uzarewicz,Dresler
, p. 181 - 195 (2007/10/03)
Cyclic secondary and tertiary allylic alcohols react with primary aliphatic alcohols in the presence of cerium(III) chloride heptahydrate to give alkyl allylic ethers. When secondary or tertiary aliphatic alcohols are used 1,3-dienes are obtained from allylic alcohols heaving the 3-methyl-2-en-1-ol moiety (3-8, 13-15).
Qualitative determination of the non-volatile reaction products of the α-pinene reaction with hydroxyl radicals
Vinckier, C.,Compernolle, F.,Saleh, A. M.
, p. 501 - 514 (2007/10/03)
This work describes the qualitative determination of the non-volatile reaction products (condensables) in the α-pinene/OH/O2/NO reaction.The study was carried out in a fast-flow reactor and the hydroxyl radicals were generated by the H + NO2-reaction.Two collection systems have been checked: a liquid nitrogen trap and an active charcoal trap.It was found that the liquid nitrogen trap was the most suitable technique since heterogenous reactions on the active charcoal surface lead to the formation of products not related to α-pinene/OH reaction.Both dichlorometane and methanol have been tried out as solvents but methanol has to be avoided since it forms a number of unwanted methanol-adducts during the extraction or analysis.The following condensables have been identified as genuine reaction products: pinonaldehyde, campholene aldehyde, trans- and cis-pinocamphone, pinol, trans-carveol, carvotaneacetone, trans-sobrerol and a ketoalcohol 5-(2-hydroxy-2-propyl)-2-methyl-2-cyclohexen-1-one.Some mechanistic aspects of the formation of these products are discussed with special attention for the role of nitric oxide.
A NEW METHOD FOR THE SYNTHESIS OF BICYCLIC ETHERS FROM TERPENOID ALCOHOLS OF THE CARANE AND MENTHANE SERIES
Polovinka, M. P.,Vyglazov, O. G.,Korchagina, D. V.,Manukov, E. N.,Barkhash, V. A.
, p. 1814 - 1826 (2007/10/02)
It was established that 2-carene-4α- and 3-carene-2α-alkylmethanols and hydroxy-p-menthadienes undergo heterocyclization in superacidic media (HSO3F-SO2FCl, -100 deg C) with the formation of bicyclic ethers containing oxabicyclooctane, oxabicyclooctane, andoxabicyclononane skeletons, depending on the structural characteristics of the initial substances.
Halogenated Terpenoids. XXIV The Bromocineoles
Carman, Raymond M.,Fletcher, Mary T.
, p. 1723 - 1738 (2007/10/02)
The bromination of cineole under a range of conditions is reported.Various bromocineoles and their properties are discussed.
