Abstract : This thesis was carried out in the laboratory of Medicinal Chemistry in Lyon on the development of analogs of hydrophobic di- or tripeptides called reversins which may modulate the chemoresistance of tumor cells associated with the expression of proteins belonging to the "ATPBinding cassette" (ABC) family. Some analogs of these reversins have been synthesized in order to increase their inhibitory activity and their bioavailability and to specify the necessary structural requirement for this activity towards two proteins, P-glycoprotein (P-gp) and the Breast Cancer Resistance Protein (BCRP). Firstly, in order to evaluate the peptide bond influence, we have synthesized aminomethylene analogs of the most active reversins as well as ketomethylene derivatives of a reference reversin. Secondly, we have undertaken the synthesis of derivatives modified at the N-terminal side chain of a reference reversin as well as constrained derivatives of this side chain to explore the conformational space in this region of ABC proteins binding. The biological activities of the synthesized analogs were evaluated on two ABC proteins, P-gp and BCRP. Initial results showed selectivity of the products towards P-gp compared to BCRP and the interaction of the N-terminal side chain with the P-gp binding site. This approach has resulted in analogs that are more active than the original reversins on P-gp especially the constrained derivatives.