Abstract: To prepare 2,3,6,3′,4′-penta-O-acetyl sucrose (6-PAS) with high purity in aqueous acetic acid solution, 6,1′,6′-tri-O-tritylsucrose penta-acetate (TRISPA) was selectively detritylated, and the products were characterized by 1HNMR, MS and FTIR. The effects of water content and reaction temperature on the selective detritylation of sucrose hydroxyl protective groups were investigated. The integrative reaction involves detritylation and acetyl migration in which the reaction selectivity was 80%. The yield and the purity by HPLC of 6-PAS were 52% and 99%, respectively.