Use of N-Pivaloyl Imidazole as Protective Reagent for Sugars

Abstract

N -Pivaloyl imidazole was prepared and used as a selective protective reagent of different monosaccharides (D-glucose, D-mannose, D-galactose, 2-acetamido-2-deoxy-D-glucose and 2acetamido-2-deoxy-β -D-glucopyranosyl azide) and lactose. A variety of pivalates were obtained with moderate or good regioselectivity.

Dynamic Combinatorial Chemistry: Lysozyme Selects an Aromatic Motif That Mimics a Carbohydrate Residue

“…The 4-methylumbelliferyl glycoside 7 was obtained by Roys procedure [11] and by using Hortons chloride. [12] Regioselective pivaloylation of hydroxyl groups at the 3 and 6 positions, [13] followed by epimerization at C-4 [14] furnished the d-galacto derivative 8. Triflate formation and nucleophilic substitution by sodium azide provided the azido intermediate 9, which after deprotection of the hydroxyl groups and catalytic hydrogenation afforded amine A.…”

Dynamic Combinatorial Chemistry: Lysozyme Selects an Aromatic Motif That Mimics a Carbohydrate Residue

“…The 4‐methylumbelliferyl glycoside 7 was obtained by Roy's procedure11 and by using Horton's chloride 12. Regioselective pivaloylation of hydroxyl groups at the 3 and 6 positions,13 followed by epimerization at C‐414 furnished the D ‐galacto derivative 8 . Triflate formation and nucleophilic substitution by sodium azide provided the azido intermediate 9 , which after deprotection of the hydroxyl groups and catalytic hydrogenation afforded amine A .…”

Synthesis of β-Cyclodextrin, Per-O-glycosylated through an Ethylene Glycol Spacer Arm

“…4,[16][17][18] Thus, the synthesis started with the glycosylation of the spacers 3-5 with D-mannose and D-galactose, the latter one in both, pyranoside and furanoside, forms. The galactofuranoside glycosyl donor 2c was prepared by treatment of D-galactose with pivaloyl imidazole 19 in DMF at 80 ºC, obtaining the mixture of anomers in 92% yield. The galactopyranosyl and mannopyranosyl donors were used as bromide derivatives 20 1a and 2a, and imidate derivatives 21 1b and 2b.…”