METHOD FOR THE RACEMIC SEPARATION OF BICYCLIC IMINO -A- CARBON ACID ESTERS

摘要

The invention relates to a process for resolving racemic mixtures of bicyclic imino- alpha -carboxylic acid esters into the components of the formula Ia and Ib IMAGE in which R1 stands for an aliphatic, cycloaliphatic, aromatic or araliphatic radical, A denotes hydrogen and B and C together form a carbon chain or C denotes hydrogen and A and B together form a carbon chain, by crystallizing diastereoisomeric salts, which comprises preparing the salts of the racemic esters with optically active O,O-diacyltartaric acids in a suitable solvent in which only one of the two diastereoisomeric salts crystallizes in optically pure form, if desired purifying the diastereoisomeric salt by recrystallization, reprecipitation or trituration, and finally adding basec to the salt to cleave it into the pure enantiomer of the formula Ia or Ib. The invention also relates to diastereoisomeric salts of an ester of the formula Ia or Ib and a diacyltartaric acid.