Patent ID: 6689905
Filing Date: 2004-02-10
Classification: C07B,C07C

Abstract:
A process for preparing stereoisomers represented by the formulae: the process comprising the steps of:a) reacting 2,6-Dimethyl-3-oxo-bicyclo[2.2.1]heptane-1-carboxylic acid, having the formula: with a chiral alcohol or chiral amine to form the diastereomeric forms of a compound of the formula: wherein R represents the residue of the respective chiral alcohol or chiral amine;b) separating the diastereomers using reversed phase chromatography; c) treating the separated diastereomers from Step b) with ammonium carbonate and an alkali metal cyanide in a volume of organic solvent/water to form spiro-fused hydantoin forms of the diastereomers having the formula: wherein R is as defined above;d) treating the resulting spiro-fused hydantoin forms of the diastereomers from Step c) with base; and e) passing each stereoisomer through an ion exchange column to yield and separate the four aminodicarboxylic acid stereoisomers of the formulae: