抄録
Regioselective functionalization of multi-functionalized substrates is one of the goals of current research toward the development of the advanced molecular transformation for the next generation. Here, we report a highly regioselective acylation of sugar derivatives with chiral nucleophilic catalysts. Treatment of a sugar derivative with 1 mol% of a catalyst and 1.1 mol eq. of isobutyric anhydride in chloroform gave the 4-acylated derivative and the 3-acylated surrogate in a 99:1 ratio in 98% yield. The corresponding 6-isomer, 2-isomer, and di-acylated isomers were not detected at all.
