1219-33-6

61049-67-0

General procedure for the synthesis of 3-(benzyloxy)-4H-pyran-4-one from 5-benzyloxy-4-oxo-4H-pyran-2-carboxylic acid: 5-benzyloxy-4-oxo-4H-pyran-2-carboxylic acid (13b) (15.87 g, 64.5 mmol) was mixed with 1-methyl-2-pyrrolidinone (160 mL) and heated and refluxed for 4 hours. After completion of the reaction, the solvent was removed by azeotropy with N,N-dimethylformamide (160 mL) under high vacuum. The residue was dissolved in dichloromethane and washed with 5% aqueous sodium hydroxide (3 x 90 mL). The organic layer was dried over anhydrous sodium sulfate, concentrated, and recrystallized from toluene to give the light yellow solid product 3-(benzyloxy)-4H-pyran-4-one (14b) (9.07 g, 70% yield).