Direct Catalytic Transformation of Olefins into α-Hydroxy Ketones with Hydrogen Peroxide Catalyzed by Peroxotungstophosphate
作者:Yasuyuki Sakata、Yuji Katayama、Yasutaka Ishii
DOI:10.1246/cl.1992.671
日期:1992.4
Aliphatic olefins were directly converted into α-hydroxy ketones with acidic aqueous hydrogenperoxide in the presence of catalytic amount of peroxotungstophosphate (PCWP) under the biphasic system using chloroform as a solvent. The acidic medium was necessary to open the resulting epoxide to vic-diol which was subsequently oxidized to α-hydroxy ketones.
The present invention relates to a new process for the generation of pyrazines consisting in the bioconversion of hydroxyketones with 1,2-diaminopropane. New tetrahydropyrazine derivatives as well as new dihydropyrazine derivatives with high flavour and low threshold properties are disclosed. Such pyrazines compounds exhibiting roasted and earthy aroma profiles may be used in the food and bevererage industry, especially chocolate, confectionery and coffee.
α-Hydroxy ketones and vic-diols were successfully oxidized to the corresponding diketones with aqueous hydrogenperoxide in the presence of a catalytic amount of peroxotungstophosphate (PCWP). This method provides a straightforward route of 1, 2-diketones which are difficult to prepare by conventional oxidation of vic-diols.