Draw and name the products of bromine water oxidation of


(a) D-mannose
(b) D-galactose
(c) D-fructose

Verified step by step guidance

1. Identify the functional groups present in each sugar: D-mannose, D-galactose, and D-fructose. Note that D-mannose and D-galactose are aldoses (containing an aldehyde group), while D-fructose is a ketose (containing a ketone group).
2. Understand that bromine water (Br2 in H2O) is a mild oxidizing agent that specifically oxidizes the aldehyde group in aldoses to a carboxylic acid, without affecting the ketone group in ketoses.
3. For D-mannose and D-galactose, draw the structure of each sugar and identify the aldehyde group at the C-1 position. Then, show the oxidation of this aldehyde group to a carboxylic acid, resulting in the formation of D-mannonic acid and D-galactonic acid, respectively.
4. For D-fructose, recognize that bromine water does not oxidize ketones. Therefore, D-fructose remains unchanged in the presence of bromine water.
5. Name the products: (a) D-mannonic acid from D-mannose, (b) D-galactonic acid from D-galactose, and (c) D-fructose remains unchanged.

Key Concepts

Bromine Water as an Oxidizing Agent

Bromine water is a solution of bromine in water that acts as a mild oxidizing agent. It can oxidize alcohols and aldehydes to their corresponding carbonyl compounds, and in the case of sugars, it can oxidize certain functional groups, leading to the formation of carboxylic acids. Understanding its reactivity is crucial for predicting the products of the oxidation of carbohydrates.

Monosaccharide Structure and Reactivity

Monosaccharides like D-mannose, D-galactose, and D-fructose have distinct structures that influence their reactivity. D-mannose and D-galactose are aldoses, containing aldehyde groups, while D-fructose is a ketose, containing a ketone group. The presence of these functional groups determines how each sugar will react with bromine water, leading to different oxidation products.

Product Identification in Oxidation Reactions

Identifying the products of oxidation reactions involves understanding the transformation of functional groups. For aldoses, oxidation typically results in the formation of carboxylic acids, while ketoses may yield different products. Recognizing these transformations is essential for accurately drawing and naming the products of the bromine water oxidation of the specified sugars.