| 摘要 |
<p>A process for the isolation of substantially pure ascorbyl-6-fatty acid ester from the products obtained by the sulphuric acid-catalyzed esterification of ascorbic acid with fatty acids comprises extracting with diethyl ketone such reaction products from the mixture remaining after the esterification reaction, hydrolysing the sulphate ester by-products in the diethyl ketone extract, removing the generated sulphuric acid from the product of this hydrolysis, isomerizing the ascorbyl-5-fatty acid ester by-product to the desired ascorbyl-6-fatty acid ester by acid catalysis in a non-polar aprotic organic solvent, and recovering the accumulated ascorbyl-6-fatty acid ester. As another aspect, the present invention provides a process for the manufacture of fatty acid esters of ascorbic acid, said process comprising the initial step of reacting ascorbic acid or an alkali metal or alkaline earth metal salt thereof with a fatty acid or with a lower alkyl ester or an alkali metal salt or alkaline earth metal thereof in concentrated sulphuric acid, and subsequent steps based on the above-described isolation process.</p> |
