| 摘要 |
PURPOSE:To obtain the titled compound in high yield, by reacting 5,6- isopropylideneascorbic acid with a stright-chain fatty acid halogenide in two stages, separately adding an acid catalyst for reaction in the second stage and carrying out deisopropylidenation in a specific solvent. CONSTITUTION:5,6-Isopropylideneascorbic acid is reacted with a straight-chain fatty acid halogenide in the presence of a basic catalyst in an organic solvent as the first-stage reaction to give 5,6-isopropylidene-2,4-di-O-(straight-chain fatty acid acryl)ascorbic acid, which is then separated and treated with an acid in acetone in the case of >=16C acyl group in the intermediate or an alcohol in the case of a <=14C acyl group to selectively carry out only deisopropylidenation and afford the titled compound. Thereby the aimed stable ascorbic acid having high preservation quality with time, blending stability with oily bases and percutaneous absorbability is obtained.
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