A catalytic method for synthesis of γ-butyrolactone, ɛ-caprolactone and 2-cumaranone in the presence of Preyssler's anion, [NaP5W30O110]14−, as a green and reusable catalyst

γ-Butyrolactone, ɛ-caprolactone and 2-cumaranone are synthesized from related diols, using Preyssler heteropolyacids, H14[NaP5W30O110] and H14[NaP5W29MoO110] as catalyst, and hydrogen peroxide as oxidizing agent. The performance of eco-friendly Preyssler catalysts was compared with H2SO4 and the catalytic activity of H2SO4 is found to be lower than Preyssler catalysts. The effects of various parameters such as amount of diol, temperature, solvent and time were studied. In all cases, the Preyssler catalyst was easily recovered and recycled with retention of their initial structure and activity.

The catalytic lactonization of 1,4-butanediol, 1,6-hexanediol and 1,2-benzene dimethanol with Preyssler catalyst and hydrogen peroxide in various solvents was studied. The results show that in all cases molybdenum substituted Preyssler catalyst is the catalyst of choice. The effects of various parameters such as amount of diol, temperature, solvent and reaction time were studied. Figure optionsDownload high-quality image (29 K)Download as PowerPoint slide