The aim of the research work carried out in this book is to synthesize new chiral N-phenylsulfonyl- -aminohydrazides from naturally occurring amino acids. The present work can be divided into three parts:- The first part is devoted to the synthesis of a series of chiral N-phenylsulfonyl- -amino acids from naturally occurring -amino acids.- The second part describes the synthesis of chiral N-phenylsulfonyl- -aminoesters by esterification of the N-phenylsulfonyl amino acids obtained previously.- The third part deals with the synthesis of chiral N-phenylsulfonyl- -aminohydrazides by condensation of the -aminoesters obtained with hydrazine.