The invention relates to new products of formula (I): ##STR00001## in which: Y represents oxygen or sulphur, Z represents C.dbd.CH2, CH--CH3 or CH2, R1 represents hydrogen, morpholinyl or the ##STR00002## radical. In which the two nitrogen atoms are linear or form a cyclic radical, X represents carbonyl, alkylene or alkenylene, linear or branched, containing at most 6 carbon atoms optionally interrupted by oxygen or sulphur, R4, R5 and R6 represent hydrogen, a protective group of the nitrogen, alkyl, cycloalkyl, aryl and arylalkyl optionally substituted, R2 represents alkyl optionally substituted by aryl, heteroaryl or --NR4R5, R3 represents alkyl, cycloalkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl optionally substituted, these products being in all isomer forms and the salts, as medicaments.