PentaacetylDglucose

Pentaacetyl-D-glucose is the fully protected form of D-glucose in which the five available hydroxyl groups are converted to acetate esters, yielding the pentaacetate. In the common D-glucopyranose form, these hydroxyl groups are located at the C1, C2, C3, C4, and C6 positions.

Preparation and properties: Pentaacetyl-D-glucose is typically prepared by acetylation of D-glucose with acetic anhydride in a basic medium such as pyridine or DMAP. The product is usually obtained as a colorless crystalline solid and is soluble in many organic solvents (for example, dichloromethane and acetone). It is stable under dry storage but hydrolyzes to D-glucose under aqueous or strongly acidic/basic conditions.

Applications: As a fully protected sugar, pentaacetyl-D-glucose serves as an important intermediate in carbohydrate synthesis. It provides a convenient entry point for the preparation of glycosyl donors and other glycosylation reagents after selective deacetylation or conversion of individual acetates. This protective strategy enables regio- and stereoselective assembly of oligosaccharides and more complex glycoconjugates while masking the reactive hydroxyl groups during intermediate steps. Deacetylation is typically performed under mild conditions (for example, Zemplén deacetylation) when the free hydroxyls are required.

See also: Other peracetylated sugars and protecting-group strategies in carbohydrate chemistry.