XANTHENE-, THIOXANTHENE- AND DIBENZOCYCLOALKENE- ALPHA-AMINO ACID DERIVATIVES

摘要

Novel cyclic amino acids which are useful in preparing biologically active peptides as well as a process for the preparation of D and L enantiomers of the cyclic amino acids are described where an N-protected derivative of the racemic cyclic amino acid is treated with (-)cinchonidine and the resulting salt resolved into the desired enantiomers, as well as derivatives thereof and valuable intermediates used in the process.