Chiral 4-pyrrolidinopyridine (PPY) analogues with dual functional side chains consisting
of indole units have been prepared from trans-4-hydroxy-l-proline. Treatment of octyl β-d-glucopyranoside with isobutyric anhydride in the presence of the catalysts gave the
6-O-acylate as the major product via acylation of a primary hydroxyl group. On the other
hand, the 4-O-acylate was obtained as the major product in 66% regioselectivity via acylation of
the secondary hydroxyl group at C-4 on treatment of octyl β-d-glucopyranoside with isobutyric anhydride in the presence of a PPY catalyst. Use
of isobutyryl chloride instead of isobutyric anhydride in the presence of the catalyst
gave the 6-O-acylate in 87% regioselectivity.
regioselective acylation - nucleophilic catalyst - glucopyranoside - chiral pyrrolidinopyridine
- organocatalyst