| abstract |
Stereoconservative process for the preparation of an (R) or (S) isomer of the compound of formula (I) having an optical purity of at least 95%, where R1 represents a hydrogen atom, a saturated or unsaturated lower alkyl group , a cycloalkyl group, or a group (CH2) mPh, where m is 0-3 and Ph is a substituted or unsubstituted phenyl group, comprising 1) O, N-dialkylation directly or in stages, of (R) - or ( S) -proline; 2) aminolysis, 3) reduction until formation of the (R) or (S) isomer of the compound of formula (I), as well as new intermediates (II) and (III) in an optically active form obtained by the aforementioned reaction steps and where R2 has the same notation as R1 above. |