With= he aim of finding new biologically active compounds in the series of functionalsubstituted unsaturated u we synthesized methyl-and phenyl-substituted 2- halogen-4-aminoethyl-2-butenolides-4 (VIIIa, b-XIVa, b) by heating, in an excess of hydrohalic acid, esters of the corresponding E-5-amino-4-hydroxy-2, 3-epoxyvaleric acids (I- VII) obtained by the method we suggested earlier [3].