Migration of the O-p-nitrophenyl group. Mechanism whereby p-nitrophenyl α-D-glycosides liberate p-nitrophenoxide in alkaline solution

Abstract

The liberation of p-nitrophenoxide from p-nitrophenyl-α-D-glucopyranoside (1) in alkaline solution involves initial O-1 → O-2 migration of the p-nitrophenyl group to give 2-O-p-nitrophenyl-D-glucose (2), followed by subsequent O-2 → O-3 migration to give the 3-ether (3)[the D-manno-analogues (4 and 5) of (2) and (3) are also formed]; in the final step the 3-ethers are converted into saccharinic acids with the release of p-nitrophenoxide anion.