Synthesis of D-Isoascorbyl Palmitate by Transesterification and Its Antioxidation Capacity

D-Isoascorbic acid (2.9 g) and con.H_2SO_4 (14 mL) are gradually mixed at 24 ℃.Methyl palmitate (3.8 g) is slowly added and the mixture is stirred for 24 h.By addition of H_2O,extraction with Et_2O,washing of the solution,removal of Et_2O and recrystalization from toluene,D-isoascorbyl palmitate (D-IAP) is obtained in 79% yield.The product is characterized by FTIR.Its antioxiation capacity in tea seed is tested according to GB/T 5009.37—1996.Preliminary results show that D-IAP is a better antioxidant than L-IAP.