(2-Nitrophenyl)acetyl: a new, selectively removable hydroxyl protecting group.

The utility of the (2-nitrophenyl)acetyl (NPAc) group for the protection of hydroxyl functions is reported. (2-Nitrophenyl)acetates are readily prepared starting from the commercially available, inexpensive (2-nitrophenyl)acetic acid, and these esters are stable under a series of common carbohydrate transformations. The NPAc group can be removed selectively using Zn and NH(4)Cl without affecting a series of common protecting groups. This new protecting group is orthogonal with the commonly used tert-butyldimethylsilyl, levulinoyl, 9-fluorenylmethoxycarbonyl, naphthylmethyl, and p-methoxybenzyl groups.