| abstract |
NEW MATERIAL:The optically active 2-substituted-3-substituted carboxylic acid ester of formula I [R 1 and R 2 are 1-40C alkyl, alkenyl or alkynyl (which may contain halogen, CN, O, N, benzene ring, etc., in the chain); R 3 is 3-40C alkyl, alkenyl or alkynyl; X is H or 2-40C alkanoyl; * represents asymmetric carbon]. n EXAMPLE: (2R,3R)-2-methyl-3-hydroxybutanoic acid methyl ester. n USE: A starting substance of an optically active compound to be used as a physiologically active substance, functional material, etc. n PREPARATION: The objective 2-substituted-3-hydroxycarboxylic acid ester having the absolute configuration of formula VIII to formula XI can be produced by subjecting a racemic compound of formula II to ester interchange reaction with an ester in the presence of a hydrolase, resolving the product into the compounds of formula III and formula IV or compounds of formula V and formula VI, converting the compounds into an optically active 2,6-cis-2,5,6- substituted-1,3-dioxan-4-one of formula VII and reacting the compound with an alcohol of formula R 5 OH. n COPYRIGHT: (C)1991,JPO&Japio |