There is disclosed an improved process for substitution of the hydroxy group at 2-position of an ascorbic acid derivative according to the following reaction scheme: ##STR1## wherein R.sup.0 is hydrogen, alkyl having 1 to 6 carbon atoms, phenyl or a group of the formula ##STR2## (wherein X is two hydrogen atoms, or acetal or ketal residue); R.sup.1 is an alkyl or alkenyl group having up to 22 carbon atoms which may be substituted with phenyl or alkoxy having 1 to 22 carbon atoms; Y is halogen or optionally substituted sulfonyloxy; R is hydrogen, or primary, secondary or tertiary alkyl having 1 to 10 carbon atoms; and Z is an alkali metal or an alkali earth metal. There is also disclosed hydrolysis of the following scheme: ##STR3## wherein R.sup.1 is as defined above; and X is acetal or ketal residue.
揭示了一种改进的过程,用于根据以下反应方案替代
抗坏血酸衍
生物的2-位羟基:##STR1##其中R.sup.0是氢,具有1至6个碳原子的烷基,苯基或具有以下式的基团##STR2##(其中X是两个氢原子,或
缩醛或
缩酮残基);R.sup.1是具有多达22个碳原子的烷基或烯基基团,可能被苯基或具有1至22个碳原子的烷氧基取代;Y是卤素或可选择取代的磺酰氧基;R是氢,或具有1至10个碳原子的一次、二次或三次烷基;Z是碱
金属或碱土
金属。还揭示了以下方案的
水解:##STR3##其中R.sup.1如上定义;X是
缩醛或
缩酮残基。