A-Pinene, oxidation

CioHi S0-56-S) see Sobrerol ( )-a-pinene oxide (Ci( H,jO 95044-43-2) see Sobrerol L-pipecolic acid... 

Corma, G.A., Eduardo Domine, M., Susarte, R.M., and Rey, G.F. (2002) MCM-41 type microporous materials containing titanium and their utilization as catalysts in a- pinene oxidation, Patent W00054880. 

Griffiths ET, SM Bociek, PC Harries, R Jeffcoat, DJ Sissons, PW Trudgill (1987) Bacterial metabolism of a-pinene pathway from a-pinene oxide to acyclic metabolites in Nocardia sp strain P183. J Bacteriol 169 4972-4979. 

Griffiths ET, PC Harries, R Jeffcoat, PW Trudgill (1987b) Purification and properties of a-pinene oxide lyase from Nocardia sp., strain P18.3. J Bacteriol 169 4980-4983. 

Acid-catalysed rearrangement of epoxides is another widely used reaction in the fine chemicals industry. Here again the use of solid acid catalysts such as zeolites is proving advantageous. Two examples are shown in Fig. 2.25 the isomerization of rsophorone oxide (Elings et al., 1997) and the conversion of a-pinene oxide to campholenic aldehyde (Holderich et al., 1997 Kunkeler etal., 1998). Both products are fragrance intermediates. 

Phthalic acid, 3-nitro-, hazard note, 53, 129 a-Pinene oxide, preparation of, 53, 18... 

More recently spinning disc reactors have been used by Wilson et alP0) to carry out catalytic reactions using supported zinc triflate catalyst for the rearrangement of a-pinene oxide to yield campholenic aldehyde. The results of this study, presented in Table 20.1, suggest that by using a supported catalyst on a spinning disc reactor it is possible to... 

Rearrangement of a-pinene oxide to campholenic aldehyde Batch Reactor Catalysed SDR... 

Reaction conditions a-pinene 3.97 mL (25 mmol) 1,4-dioxane 40 mL oxidant air (15 mL/min) reaction time = 24h. Conversion and product composition were determined by GC and identified by GC-MS, Minor amounts of rearranged products of a-pinene oxide also formed. 

The catalysts Co-CMS5 and C0-CMS6 have also been tested for the air oxidation of a-pinene. In both the cases air oxidation commences quickly with the formation of a-pinene oxide, verbenol and verbenone as the main products along with other rearranged products as observed in the reactions described above. A conversion of 50.6% and 48.0% are observed for Co-CMSS and C0-CMS6 respectively after 24h (Table 6). 

The catalytic properties Co-POM/Si02 were assessed in oxidation of IBA to isobutyric acid [96] and a-pinene to verbenol/verbenone [97] with molecular oxygen as well as in a-pinene/lBA co-oxidation to produce the corresponding epoxide and carboxylic acid [97]. In turn, the catalytic performance of Ti-POM/Si02 was examined in a-pinene oxidation to... 

Table 15) highlights the stability of this system compared to the PS/MTO system (entry 6, Table 15), which shows a decrease in activity during recycling. This difference in behaviour may be due to the weaker interaction between MTO and the PS polymer, which is only accomplished by the physical envelopment of the benzene ring. The PVP/MTO combination was successfully used for other compounds of biological interest, such as ter-penes. Even highly sensitive terpenic epoxides, hke a-pinene oxide, can be obtained in excellent yields using polymer-supported MTO catalysts [73] (Scheme 20, Table 16). 

Campholenic Aldehyde Manufacture. Campholenic aldehyde is readily obtained by the Lewis-acid-catalyzed rearrangement of a-pinene oxide. It has become an important intermediate for the synthesis of a wide range of sandalwood fragrance compounds. Epoxidation of (+)- Ct-pinene (8) also gives the (+)-o -a-pinene epoxide [1686-14-2] (80) and rearrangement with zinc bromide is highly stereospecific and gives (-)-campholenic aldehyde... 

Regeneration of spent reagent is easy, and no loss in peroxide content is seen even over several recycles. Physical properties of the material are essentially unchanged. Labile epoxides, such as the industrially important a-pinene oxide can also be prepared in good yield under relatively mild conditions. This may be attributed to the heterogeneous nature of the system, which means that the solution phase is non-acidic. 

Conversion (mol.%) a-pinene oxide 1,2 pinane diol conversion efficiency... 

The submitters purchased a-pinene oxide from F.M.C. Corporation. However, since the compound is no longer available, the checkers prepared it from a-pinene as follows. Into a three-necked round-bottomed flask fitted with a 50-ml. dropping-funnel, a thermometer, and a magnetic stirring bar are placed 22.0 g. (0.102 mole) of ra-chloroperbenzoic acid (Note 6), 11.0 g. (0.131 mole) of sodium bicarbonate, and 250 ml. of dichloromethane. The suspension is stirred with a powerful stirrer while being cooled with an ice-salt bath. To this mixture is added dropwise a solution of 13.6 g. (0.10 mole) of a-pinene (Note 7) in 20 ml. of dichloromethane at a rate such that the inner temperature is kept between 5-10° (Note 8). During... 

Pinocarveol has been prepared by the autoxidation of a-pinene,5 by the oxidation of /S-pinene with lead tetraacetate,6 and by isomerization of a-pinene oxide with diisobutylalumi-num,7 lithium aluminum hydride,8 activated alumina,9 potassium ferf-butoxide in dimethylsulfoxide,10 and lithium diethylamide.11 The present method is preferred for the preparation of pinocarveol, since the others give mixtures of products. It also illustrates a general method for converting 1-methylcy-cloalkene oxides into the corresponding exocyclic methylene alcohols.11 The reaction is easy to perform, and the yields are generally high. 

An interesting example, although it cannot be described as functional interconversion but rather as isomerisation, was reported by Motherwell and collaborators in 2004 [58]. In this case a polymer was imprinted with a /ram-carvyl amine (97), which was used as TSA, for the isomerisation of a-pinene oxide (98) to trans-carveol (99) that was obtained with 45% yield. 

Weber e.t al. utilized dinuclear (i-oxo iron(III) phthalocyanines 18 as catalysts in the aerobic oxidation of a-pinene lg, resulting in the formation of trans-verbenol 2g, verbenone 3g and a-pinene oxide 4g in almost equimolar amounts. Additionally, 3-pinen-2-ol 19 was obtained (Scheme 3.28) [119]. 

Table 1 Comparison of the Best SDR Runs with Batch Results for Conversion of a-Pinene Oxide to Campholenic Aldehyde...

Hughes P. R. (1975) Pheromones of Dendroctonus origin of a-pinene oxidation products present in emergent adults. J. Insect Physiol. 21, 687-691. 

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