66141-68-2Relevant academic research and scientific papers
Selective photosensitized oxidation and its catalytic regulation of monoterpene with molecular oxygen in different reaction media
You, Kuiyi,Yin, Dulin,Mao, Liqiu,Liu, Pingle,Luo, He'An
, p. 321 - 325 (2011)
The photo-catalytic oxidation of α-pinene, β-pinene and limonene with molecular oxygen sensitized by tetrachlorotetraiodo-fluorescein sodium salt (RB) has been studied in different reaction media under green light irradiation. Simple and efficient photosensitized oxidation equipment was employed successfully to improve the efficiency of the photosensitized reaction. The results indicate that the photosensitized oxidation products can be directly obtained without after-treatment by reductive reagent. Furthermore, it was found that the product distributions are remarkably affected by reaction media, and that N,N-dimethylformamide (DMF) can regulate the selectivity to products. In particular, the good selectivity (85%) to the main product (myrtenal) and the excellent conversion (99%) were obtained in the absence of any other catalysts when DMF was used as reaction solvent in the photosensitized oxidation of β-pinene. Moreover, the possible photosensitized oxidation reaction mechanism in different media was suggested in the present work.
Heteropoly acid catalysts for the synthesis of fragrance compounds from biorenewables: Isomerization of limonene oxide
Costa, Vinicius V.,Da Silva Rocha, Kelly A.,Kozhevnikov, Ivan V.,Kozhevnikova, Elena F.,Gusevskaya, Elena V.
, p. 244 - 250 (2013/04/10)
The liquid-phase isomerization of limonene oxide was studied in the presence of heteropoly acid catalysts in aprotic solvents in homogeneous and heterogeneous systems. Among the catalysts were bulk and silica-supported tungstophosphoric acid H3PW12O40 and its acidic Cs salt Cs0.5H0.5PW12O40 (CsPW). The reaction gave dihydrocarvone, a valuable fragrance intermediate, as the main product with turnover numbers of up to 8000. The nature of the solvent had a strong effect on reaction rate and selectivity. CsPW (0.1 mol%) was found to be a highly efficient and truly heterogeneous catalyst for this reaction, providing 82% yield of dihydrocarvone in 1,4-dioxane as a solvent under ambient conditions. This simple catalytic method represents economically attractive route to industrially important compounds starting from bio-renewable substrates easily available from essential oils. The Royal Society of Chemistry 2013.
Mixed disproportionation versus radical trapping in titanocene(III)-promoted epoxide openings
Justicia, José,Jiménez, Tania,Morcillo, Sara P.,Cuerva, Juan M.,Oltra, J. Enrique
experimental part, p. 10837 - 10841 (2010/02/28)
The formation of either deoxygenation products or allylic alcohols from epoxides is observed when these substrates are treated with Cp2TiCl under anhydrous conditions. It seems that processes via trisubstituted radicals give allylic alcohols whereas processes via disubstituted radicals may give deoxygenation products or allylic alcohols depending on the structure of the original epoxide. This method allows a controlled access to these functional groups, providing a useful tool in organic synthesis. A mechanistic discussion for these transformations is reported.
Thermal degradation of terpenes: Camphene, Δ3-carene, limonene, and α-terpinene
Mcgraw, Gerald W.,Hemingway, Richard W.,Ingram Jr., Leonard L.,Canady, Catherine S.,Mcgraw, William B.
, p. 4029 - 4033 (2007/10/03)
Emissions from wood dryers have been of some concern for a number of years, and recent policy changes by the Environmental Protection Agency have placed emphasis upon the gaseous emissions that lead to the formation of particulate matter as small as 2.5 μm diameter. In this qualitative study, camphene, Δ3-carene, limonene, and α-terpinene were thermally degraded in the presence of air to determine the number and kind of oxidative degradation products that might be expected under drying conditions used in processing wood products. Various chromatographic methods were used to isolate the products for proof of structure by NMR and/or GC-MS. The degradation products resulted from dehydrogenations, epoxidations, double bond cleavages, allylic oxidations, and rearrangements. A number of compounds not previously associated with the thermal degradation of these terpenes were identified. Emissions from wood dryers have been of some concern for a number of years, and recent policy changes by the Environmental Protection Agency have placed emphasis upon the gaseous emissions that lead to the formation of particulate matter as small as 2.5 μm diameter. In this qualitative study, camphene, Δ3-carene, limonene, and α-terpinene were thermally degraded in the presence of air to determine the number and kind of oxidative degradation products that might be expected under drying conditions used in processing wood products. Various chromatographic methods were used to isolate the products for proof of structure by NMR and/or GC-MS. The degradation products resulted from dehydrogenations, epoxidations, double bond cleavages, allylic oxidations, and rearrangements. A number of compounds not previously associated with the thermal degradation of these terpenes were identified.
Pd-containing catalytic system for oxidative acetoxylation of alkenes
Romanenko,Tormyshev,Shteingarts
, p. 1549 - 1562 (2007/10/03)
Four-substituted cyclohexenes were used as examples for revealing the substituent effect on composition of products obtained by oxidative acetoxylation of alkenes catalyzed with Pd(II) acetate. The distribution of products is rationalized on assumption of relative stability of allylic anions and steric strains in (π-allyl)palladium intermediates. Stereoselective yield of trans-substituted endo-acetates is due to stabilizing effect of lower unoccupied orbital of the forming C-OAc bond and occupied orbitals of pseudoaxial C-H bonds at the cycle in the transition states. The substrates capable of this reaction are limited to alkenes with insignificant steric shielding of the double bond. The study of the influence on the process of the characteristics of oxidant used in the catalytic system revealed that the most significant difference is observed between catalysts prepared as homogeneous oxidative systems and those containing heterogeneous oxidant MnO2 or TiO2 as additive. 1998 MAHK "Hayka/Interperiodica".
TERPENOIDS OF THE ESSENTIAL OIL OF Ledum palustre
Klokova, M. V.,Khan, V. A.,Dubovenko, Zh. V.,Pentegova, V. A.,Berezovskaya, T. P.,Serykh, E. A.
, p. 278 - 281 (2007/10/02)
The chemical composition of the essential oil of crystal tea ledum of the ordinary variety growing in Western Siberia has been studied.Eighteen terpenoids have been isolated and identified from their spectral characteristics.Linalyl acetate, α-terpenyl ac
Stereoselective Cyclization assisted by the Selenyl Group. Biogenetic-type Synthesis in the p-Menthane Series
Kametani, Tetsuji,Kurobe, Hiroshi,Nemoto, Hideo
, p. 756 - 760 (2007/10/02)
Acid-catalysed cyclization of the β-hydroxyselenide (3), derived from linalyl acetate (1), afforded the trans-p-menthanes (4) and (5), the structures of which were confirmed by their transformation into (6), (11), (8), and (13), and alternative syntheses of these compounds.The structure determination of some products obtained by the reaction of limonene and α-terpineol epoxides with phenylselenium anion was also carried out.
