| 摘要 |
PURPOSE:To prepare the title compound useful as an intermediate of L-ascorbic acid for medical use, economically, in an industrial scale, by oxidizing diacetonesorbose with oxygen(-containing) gas, in an alcohol, in the presence of a Pd-containing catalyst. CONSTITUTION:The objective diacetone ketogulonic acid ester of formula II (R1,2 are H, lower alkyl, aryl, etc.; R3 is lower alkyl) is prepared by oxidizing diacetonesorbose of formula I in an alcohol solvent with an oxygen(-containing) gas, in the presence of a Pd-containing catalyst. The catalyst pref. contains Pd and at least one metal (compound) selected from Pb, Hg, and Tl. EFFECT:The reaction can be carried out in one step. |
