Synthesis of food-grade 6-O-ascorbyl fatty esters and their semi-synthesis from low-value oils as resources

A high yielding, cost-effective, and regioselective methodology for the gram-scale synthesis of 6-O-ascorbyl esters has been developed by the esterification of l-ascorbic acid with a variety of saturated long-chain fatty acids in the presence conc. H2SO4. A renewable food-grade solvent, p-cymene, was efficiently used in the process to affect the product separation from the reaction mixture while the physical methods, e.g., cooling and centrifugation, were applied for product isolation in good yields (70–82%) and purity (> 99%). The methodology was scaled up for the production of 6-O-ascorbyl palmitate (45 g) in 80% yields and > 99% purity. A direct application of the developed method on low-value fats and oils resulted in the synthesis of a mixture of 6-O-ascorbyl esters for use as antioxidants in food products.