33171-49-2

Upstream product

• 1686-14-2 2α,3α-epoxypinane 
• 80-56-8 Pinene 
• 79-15-2 N-bromoacetamide 
• 14575-92-9 2,3-epoxy-cis-pinane 
• 18680-27-8 pinanediol 
• 1686-14-2 (1R,2R,4S,6R)-2,7,7-trimethyl-3-oxatricyclo[4.1.1.0.^2,4]octane 
• 1686-14-2 α-pinene epoxide 

Relevant academic research and scientific papers

Synthesis of Fencholenic Aldehyde from α-pinene Epoxide on Modified Clays

The conditions for isomerization of α-pinene epoxide (2,3-epoxypinane) on modified clays that gave comparatively high contents (33.0%) of fencholenic (iso-campholenic) aldehyde in the product mixture were determined. An effective method for isolating it w

H- and Fe-modified zeolite beta catalysts for preparation of trans-carveol from α-pinene oxide

The isomerisation of α-pinene oxide has been intensively investigated for selective preparation of campholenic aldehyde, a compound used in the synthesis of fragrances. Selective preparation of another product of α-pinene oxide rearrangement, trans-carveol, still remains a challenging task. Trans-carveol is a highly valuable compound used in perfume bases, food flavour compositions and as an active pharmaceutical substance in chemoprevention of mammary carcinogenesis. In the present work zeolite beta with different SiO2/Al2O3 molar ratios was modified by iron, characterised and tested per se and in the modified form for trans-carveol preparation from α-pinene oxide. The isomerisation reaction was carried out in a polar basic solvent N,N-dimethylacetamide at 140 °C. The activities and selectivities of the catalysts were correlated with their acid properties and with the iron content.

H- and Fe-modified zeolite beta catalysts for preparation of trans-carveol from α-pinene oxide

The isomerisation of a-pinene oxide has been intensively investigated for selective preparation of campholenic aldehyde, a compound used in the synthesis of fragrances. Selective preparation of another product of α-pinene oxide rearrangement, trans-carveol, still remains a challenging task. Trans-carveol is a highly valuable compound used in perfume bases, food flavour compositions and as an active pharmaceutical substance in chemoprevention of mammary carcinogenesis. In the present work zeolite beta with different SiO2/Al2O3 molar ratios was modified by iron, characterised and tested per se and in the modified form for trans-carveol preparation from a-pinene oxide. The isomerisation reaction was carried out in a polar basic solvent N, N-dimethylacetamide at 140 °C. The activities and selectivities of the catalysts were correlated with their acid properties and with the iron content.

Isomerization of α-pinene oxide using Fe-supported catalysts: Selective synthesis of campholenic aldehyde

α-Pinene oxide, an oxygenated derivative of α-pinene, can be converted into various valuable substances useful as flavour, fragrance and pharmaceutical compounds. Campholenic aldehyde is one of the most desired products of α-pinene oxide isomerization being a valuable intermediate for the production of sandalwood-like fragrances. Iron modified zeolites Beta-75 and ZSM-5, mesoporous material MCM-41, silica and alumina were prepared by two methods (impregnation and solid-state ion exchange) and tested for selective preparation of campholenic aldehyde by isomerization of α-pinene oxide. The characterization of tested catalyst was carried out using scanning electron microscope analysis, nitrogen adsorption measurements, pyridine adsorption-desorption with FTIR, X-ray absorption spectroscopy measurements, XPS-analysis, 29Si MAS NMR and 27Al MAS NMR and X-ray diffraction. The isomerization of α-pinene oxide was carried out in toluene as a solvent at 70 C. The main properties influencing the activity and the selectivity are the acidic and structural properties of the tested catalysts. The highest selectivity of 66% was achieved at complete conversion of α-pinene oxide with Fe-MCM-41.

Influence of the Br?nsted and Lewis acid sites on the catalytic activity and selectivity of Fe/MCM-41 system

The system Fe2O3/MCM-41, with high iron dispersion, was synthesized in order to introduce Lewis acid sites into the MCM-41 structure. Two calcination atmospheres (inert and oxidant) were used to produce iron nanoclusters with different structural properties. Besides, a silylation treatment was realized on both solids with the aim of neutralizing the Br?nsted acidity associated with the MCM-41 silanol groups. The samples were characterized by atomic absorption spectroscopy, X-ray diffraction at low angles, N2 adsorption, temperature-programmed reduction, Fourier transform infrared spectroscopy, nuclear magnetic resonance of 29Si, and M?ssbauer spectroscopy. The influence of the structural changes of the nanoclusters and the effect of the simultaneous presence of Lewis and Br?nsted acid sites were evaluated studying the product distribution from the α-pinene oxide isomerization reaction. It was determined that the Br?nsted acidity of the Fe/MCM-41 system has not the sufficient acid strength to modify the product distribution which is mainly governed by the Lewis sites.

Pinacol-type rearrangement catalyzed by Zr-incorporated SBA-15

Highly ordered zirconium-incorporated SBA-15 materials, designated as Zr-SBA-15, with Zr/Si ratios up to 10.8 mol% were one-pot synthesized in a self-generated acidic environment. Zr was incorporated into the SBA-15 framework as isolated Zr species, and it also formed superficial zirconia clusters with two or more Zr centers on the pore walls when the Zr/Si ratio was higher than 3 mol%. The acid amounts of Zr-SBA-15 materials increased linearly with Zr loading, but the acidities were lower than those of commercially available HY and ZSM-5 zeolites. However, when used as the catalysts in liquid phase pinacol-type rearrangement, one-pot synthesized Zr-SBA-15 materials, especially those with superficial zirconia clusters, were the most efficient catalysts. The pinacolone yield of 2.7 g/g catal h and selectivity of 81% were achieved in 1 h over Zr-SBA-15 with a Zr/Si ratio of 10.8 mol%. Moreover, Zr-SBA-15 was also efficient in catalyzing the rearrangement of bulky 2,3-pinanediol to yield camphor as the major product through hydrogen migration.

The thermolysis of α-pinene and verbenone epoxides in supercritical solvents

Thermal transformations of α-pinene and verbenone epoxides were studied in supercritical solvents with complex compositions, including CO 2, lower alcohols (ethanol and isopropanol), and water, over the temperature and pressure ranges 387-575 K and 135-215 atm. The main product from α-pinene epoxide in a supercritical solvent containing water was campholenic aldehyde and pinocamphone; the total content of these products in the reaction mixture was 80%. Suggestions concerning the mechanism of the thermal isomerization of α-pinene epoxide depending on the acidity of supercritical solvents were made. The direction of verbenone epoxide transformations was independent of the presence of water in the mixture. The main identified products were ketoalcohols with para-menthane and camphane frameworks.

Copper(II) tetrafluroborate-promoted Meinwald rearrangement reactions of epoxides

Epoxides undergo a highly efficient Meinwald rearrangement in the presence of catalytic quantities of copper(II) tetrafluoroborate to give carbonyl compounds in high yields and with excellent selectivity. The low toxicity and ease of handling of this reagent make it an attractive alternative to the more corrosive or costly Lewis acids frequently employed.

Rearrangements of 2,3-epoxy-cis-pinane in acid media

Treatment of 2,3-epoxy-cis-pinane with the system HSO3F-SO2FCI at -110°C, followed by quenching with MeOH-Et2O, gives rise to a mixture of 3α-methoxy-1β,8,8-trimethyl-cis-2-oxabicyclo[3.3.0]-octane, pinol, and trans-6-methoxy-4-(1-methoxy-1-methylethyl)-1-methylcyclohexene. A mechanism of this rearrangement was proposed on the basis of molecular-mechanics and quantum-chemical calculations. Isomerization of the title compound over β-zeolite at 20°C yields a mixture of 2,2,3- and 2,2,4-trimethyl-3-cyclopentene-1-acetaldehydes.

Ring Opening of α-Pinene Epoxide

The acid-catalysed opening of the epoxide ring of α-pinene epoxide (2α,3α-epoxypinene) has been shown to proceed without participation of cyclobutane ring expansion in the rate-determining step.The reaction cannot proceed by initial C-O bond fission, as intermediates generated by either fission are on other reaction pathways.It is suggested that the reaction proceeds by fission of the C-C bond to give a heterocyclic intermediate, which can ring open, and finally expand the cyclobutane ring in the product-determining step.Reactions which could proceed by a similar mechanism are discussed.The corresponding reaction of β-pinene epoxide (2β,10-epoxypinene) in which the epoxide ring is not part of a strained bicyclic system, proceeds via this route to the extent of only 0.5percent.The main reaction involves conventional C-O bond fission.