| abstract |
The derivatives of cyclic amino acids have the formula …<IMAGE>… in which… R<1> denotes hydrogen, alkyl, alkenyl or (subst.) aryl, R<2> denotes hydrogen, alkyl, hydroxyl, alkoxy, (subst.) aryl, (subst.) aryloxy or (subst.) aroyl, or R<1> and R<2> together represent (subst.) benzylidene or R<1> and R<2> together with the carbon atom carrying them represent (subst.) cycloalkyl, R<3> denotes hydrogen, hydroxymethyl, formyl, (subst.) alkenyl, (subst.) carboxylatocarbonyl, (subst.) carbamoylatocarbonyl or (subst.) trifluoromethylcarbonyl, A represents a cyclic amino acid, X denotes oxygen, imino or N-alkylimino, m is 0-5 and n is 0 or 1. |