Predict the products formed when the following sugars react with excess acetic anhydride and pyridine.
(b) β-D-ribofuranose

Acetic anhydride is a powerful acetylating agent commonly used in organic chemistry to introduce acetyl groups into alcohols and sugars. When sugars react with acetic anhydride, the hydroxyl groups (-OH) on the sugar molecules are converted into acetyl groups (-OCOCH3), resulting in the formation of acetylated sugars. This reaction is important for modifying the solubility and reactivity of sugars.

Pyridine is often used as a base in organic reactions, including acetylation processes. It helps to deprotonate the hydroxyl groups of sugars, making them more nucleophilic and thus more reactive towards acetic anhydride. This catalytic role enhances the efficiency of the acetylation reaction, facilitating the formation of the acetylated products.

The structure of sugars, such as b-D-ribofuranose, influences their reactivity in chemical reactions. b-D-ribofuranose is a five-membered ring sugar with specific hydroxyl groups that can be acetylated. Understanding the stereochemistry and functional groups present in the sugar is crucial for predicting the products of the reaction, as different hydroxyl groups may react differently under the same conditions.