5503-12-8Relevant articles and documents
Limonene oxyfunctionalization over Cu-modified silicates employing hydrogen peroxide and t-Butyl hydroperoxide: Reaction pathway analysis
Vaschetti, Virginia M.,Cánepa, Analía L.,Barrera, Deicy,Sapag, Karim,Eimer, Griselda A.,Casuscelli, Sandra G.
, (2018/11/23)
Limonene oxidation over Cu-nanostructured mesoporous materials was studied. Three solids with different copper content were synthesized employing the template-ion exchange method, and physically-chemically analyzed by a multi-technical characterization. The performance of the molecular sieves as catalysts in the liquid phase oxyfunctionalization of limonene, employing hydrogen peroxide (H2O2) or t-butyl hydroperoxide (TBHP) as oxidants was evaluated. All synthesized Cu-MCM materials were active in the reaction. The obtained results showed that the used oxidant had an important influence on the products distribution under the employed conditions. With H2O2, compounds of high added value such as limonene oxide, carveol and carvone were mainly obtained. Meanwhile, with TBHP, limonene hydroperoxide turned out to be the major product. Finally, a reaction mechanism was proposed for each oxidant.
A chemoenzymatic, preparative synthesis of the isomeric forms of p-menth-1-en-9-ol: Application to the synthesis of the isomeric forms of the cooling agent 1-hydroxy-2,9-cineole
Serra, Stefano,Fuganti, Claudio,Gatti, Francesco G.
experimental part, p. 1031 - 1037 (2009/04/05)
A preparative-scale synthesis of the four p-menth-1-en-9-ol isomers 2a-5a has been achieved by means of two chemoenzymatic processes. Both synthetic pathways start from the enantiomeric forms of limonene that are converted into p-mentha-1,8-dien-9-al isomers 12 and 15. The baker's yeast mediated reduction of the latter aldehydes afforded compounds 3a and 5a, respectively, with very high enantioselectivity. Moreover, chemical reduction of 12 and 15 gives the mixtures of enantiopure diastereoisomers 2a/3a and 4a/5a, respectively. PPL (Porcine pancreas lipase) mediated resolution of the latter mixtures followed by fractionating crystallization of derivatives 2b-5b allowed the enantio- and diastereoisomerically pure alcohols 2a-5a to be obtained. Compounds 2a-5a have then been used as starting materials for the preparation of four isomers of the cooling agent 1-hydroxy-2,9-cineole (6-9). Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Stereochemical aspects of the bioreduction of the conjugated double bond of perillaldehyde
Fronza, Giovanni,Fuganti, Claudio,Pinciroli, Matteo,Serra, Stefano
, p. 3073 - 3077 (2007/10/03)
A study on the regioselective reduction of the conjugate double bond of perillaldehyde is described. The chemical reduction of this substrate was investigated in order to provide a straightforward access to the relevant natural flavour, dihydroperillaldehyde. The biological reduction of both natural (S)-(-)-perillaldehyde and synthetic (R)-(+)-perillaldehyde was accomplished by means of fermenting baker's yeast. The latter microorganism converted, with different diastereoselectivity, the (S)- and (R)-enantiomers into the corresponding trans and cis saturated alcohols, respectively. The origin of the hydrogen atoms added to the double bond was studied by deuterium labelling experiments and 2H NMR measurements that clearly demonstrate a different mechanism of the biohydrogenation of the two enantiomeric forms of perillaldehyde.