HUP9903004A3 - Process for preparing 3-pyrroline-2-carboxylic acid derivatives - Google Patents

Abstract

Preparation of 3-pyrrolin-2-carboxylic acid derivatives of formula (I) by elimination of the sulphonic acid residue in (II) and, if required, followed by enzymatic conversion of the obtained ester into the optically-active free acid: R1 =H, 1-6C alkyl, Bz (optionally substituted on the Ph ring), allyloxycarbonyl, 1-6C alkyloxycarbonyl, benzyloxycarbonyl or 1-4C alkylcarbonyl, or R1 may be bound to the C-terminus of an amino acid (which may be N-alkylated or N-acylated); R2 = OH, 1-4C alkyloxy, benzyloxy or NR3R4; R3, R4 = H, 1-4C alkyl, or Bz or Ph (where in either case the aromatic ring may be 1-3 fold substituted by Me, MeO, OH, CN or halo), and R5 = 1-4C alkyl or Bz.