Synthesis of 2-substituted aminothiazol-4(5H)-ones proceeding from carboxylactones

New representatives of 2,2,4-trisubstituted butano-4-lactones were synthesized. By a series of transformations the corresponding γ-carboxylactones were obtained. The latter served as starting compounds for preparation of heteryl-linked lactones, 5-[5-{(alkoxymethyl)-2-oxotetrahydrofuran-3-yl}methyl]-2-arylaminothiazol-4(5H)-ones.