PROCEDURE FOR THE PREPARATION OF MONO-, DI- AND TRICYCLIC AMINO ACIDS AND INTERMEDIATES TO THIS PROCEDURE AND A PROCEDURE FOR THEIR PREPARATION

摘要

The invention relates to a process for preparing compounds of the formula I IMAGE I in which R stands for hydrogen, alkyl or aralkyl and R1 to R5 are identical or different radicals, (substituted) alkyl, cycloalkyl or (substituted) aryl or in which the pairs of radicals R1 and R2, R2 and R3, and R4 and R5 together with the carbon atom(s) supporting them form a mono- or bicyclic ring system and the other radicals are hydrogen, by treating a compound of the formula II IMAGE II in which R and R1 and R5 have the abovementioned meaning and R6 and R7 denote alkyl or aralkyl or together with the nitrogen atom supporting them form a heterocycle which can additionally contain an oxygen atom, with a reducing agent.