Patent ID: 8030514

Claim:
A crystalline compound of Formula IIa-2a having an enantiomeric purity higher than 95% enantiomeric excess, wherein: R 1 is an alkyl, an alkenyl, an alkynyl, an aryl, or an aralkyl, each of which is unsubstituted or substituted with one or more substituents selected from the group consisting of halogen, alkyl, aryl, alkoxyl, aryloxy, thioalkoxyl, thioaryloxy, alkylamino, arylamino, cyano, pyridinyl, thiophenyl, furanyl, imidazolyl, morpholinyl, oxazolinyl, piperidinyl, piperazinyl, tetrahydropyranyl, pyrrolidinyl, and pyrrolidinonyl; with the proviso that R 1 is not unsubstituted C 1-4 alkyl.