Efficient stereoconservative synthesis of 1-substituted (S)- and
申请人:Astra Lakemedel Aktiebolag
公开号:US05300660A1
公开(公告)日:1994-04-05
Stereoconservative method for preparation of an (R)- or (S)-isomer of the compound of the formula I with at least 95% optical purity ##STR1## wherein R.sup.1 is a hydrogen atom, a saturated or unsaturated lower alkyl group, a cycloalkyl group, or a group (CH.sub.2).sub.m Ph wherein m is 0-3 and Ph is a substituted or unsubstituted phenyl group including 1) O,N-dialkylation, directly or stepwise of (R)- or (S)-proline 2) aminolysis 3) reduction to formation of the (R)- or (S)-isomer of the compound of the formula I, and new intermediates II and III in optical active form obtained by the reaction steps above and wherein R.sup.2 is defined as R.sup.1 above. ##STR2##