The general procedure for the synthesis of dihydro-3(2H)-furanone from 3-hydroxytetrahydrofuran was as follows: 3-hydroxytetrahydrofuran (3-OH-THF, 60.6 g, 0.68 mol, 1.0 eq.) was added to a 1 L three-necked flask, followed by the addition of dichloromethane (DCM, 620 mL) and 2,2,6,6-tetramethylpiperidin-1-oxyl radical (TEMPO 1.08 g, 0.0069 mol, 0.01 equiv). The reaction system was cooled to -5°C. Trichloroisocyanuric acid (TCCA, 159.6 g, 0.68 mol, 1.0 eq.) was added in batches while maintaining the temperature at -5°C to 0°C. The reaction mixture was gradually warmed up to room temperature and the reaction progress was monitored by gas chromatography-mass spectrometry (GC-MS). The reaction was completed after about 1 h. The product yield was 95% by GC area percentage analysis.
