Two new methods for selective hydration of 1, 1, 4-trisubstituted 2-butyne-1, 4-diols (1) to give 4, 5-dihydro-3 (2H)-furanone derivatives are reported. The first involves selective monoacetylation of the less hindered hydroxyl group of 1 followed by Ag (I)-catalyzed rearrangement and cyclization to give 3-acetoxy-2, 2, 5-trisubstituted 2, 5-dihydrofurans (2). Final hydrolysis yielded 2, 2, 5-trisubstituted 4, 5-dihydro-3 (2H)-furanones. Oxidation of ...