| abstract |
The present invention relates to a racemic mixture of enantiomers of a compound of formula (1a), which is mixed with a dividing compound having specific stereospecificity in a solvent to form a solution and which can be combined with one or more (but not all) enantiomers. By mixing with to form a precipitate containing at least one of the enantiomers, collecting and purifying the precipitate, or collecting a solution containing other enantiomers and recrystallizing the enantiomers contained in the solution, A method of partitioning the enantiomers of a compound is:n n n n n n n n n n Wheren n n Each substituent is the same as defined in the specification, and R 4 or R 5 may contain one or more asymmetric centers. |