PROCESS FOR THE PREPARATION OF MONOCYCLIC, BICYCLIC AND TRICYCLIC AMINOACIDS

摘要

of the disclosure: The invention relates to a process for the preparation of compounds of the formula I < IMG > in which R represents hydrogen, alkyl or aralkyl, and R1 to R6 denote identical or different radicals hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, cycloalkenylalkyl, aralkyl or aryl, both being monosubstituted, disubstituted or trisubstituted in the aryl moiety by alkyl, alkoxy, hydroxyl, halogen, nitro, methylenedioxy and/or cyano, or in which two of the radicals R1 to R6, together with the carbon atom(s) bearing them form a monocyclic or bicyclic ring system, and the remaining radicals are hydrogen, which process comprises converting, with an oxidizing agent in the presence of a silver salt, a pyrrolidine derivative of the formula II into a .DELTA.1pyrroline derivative of the formula III, reacting the latter with hydrogen cyanide or a metal cyanide to form a nitrile of the formula IV, and subjecting the latter to solvolysis with a compound of the formula ROH. The compounds of the formula I are valuable intermediates in the preparation of pharmaceuticals, especially of angiotensin converting enzyme.