Question

Convert each chair conformation to an open-chain form and then to a Fischer projection. Name the monosaccharide you have drawn.

Short answer

Question: Convert the given chair conformation of a monosaccharide to an open-chain form, translate it into a Fischer projection, and identify the monosaccharide.

Step-by-step solution

Identify the chair conformation

Analyze the given chair conformation and note its key features, such as the position of hydroxyl groups and the anomeric carbon. Identify if the conformation is alpha or beta based on the position of the hydroxyl group on its anomeric carbon.

Draw the open-chain form

Based on the chair conformation's features, draw the open-chain form (i.e., the straight-chain form) of the monosaccharide. This will include all carbons and hydroxyl groups in the linear structure, maintaining their order and orientation as in the chair conformation.

Convert the open-chain form to a Fischer projection

Transform the open-chain form into a Fischer projection by arranging the carbon atoms vertically, with the highest numbered carbon at the top, the second-highest below it, and so on. Draw bonds between adjacent carbons, and place hydroxyl groups to the left or right of each carbon according to their position in the open-chain form. In a Fischer projection, horizontal lines represent bonds coming out of the plane (towards you), and vertical lines represent bonds going into the plane (away from you).

Name the monosaccharide

Based on the Fischer projection obtained, identify and name the monosaccharide. You can do this by comparing it with Fischer projections of known monosaccharides (e.g., glucose, fructose, mannose, etc.). Determine if the monosaccharide is D or L by looking at the position of the hydroxyl group on the penultimate carbon: if the hydroxyl group is to the right, it is a D-monosaccharide; if it is to the left, it is an L-monosaccharide.