71-23-8

123-76-2

645-67-0

General procedure for the synthesis of propyl 4-oxopentanoate from n-propanol and acetylpropionic acid: the esterification of acetylpropionic acid was carried out in a 50 mL round-bottomed flask fitted with a reflux condenser tube. In a typical catalyzed reaction, catalyst (40 mg) was added to a mixture of acetylpropionic acid and n-propanol, where the molar ratio of acetylpropionic acid to n-propanol was 1:8 (with n-propanol acting as both the reactant and the solvent), and the mixture was subsequently magnetically stirred for 2 hours at 333 K. The reaction was carried out in a 50 mL round bottom flask equipped with a reflux condenser tube. After the reaction reached the predetermined time, a portion of the reaction mixture was taken and separated by filtration and the filtrate was analyzed by gas chromatography (GC) equipped with a flame ionization detector and a capillary column. All the compounds were characterized by their spectral data (1H NMR) and compared with the data reported in literature.