Question

L-galactose can be prepared from D-galactose by a route that begins with oxidation to D-galactaric acid, which cyclizes to form two six-membered-ring lactones. After separating the lactones and reducing them with sodium amalgam, one lactone returns D-galactose while the other one yields L-galactose.

Draw the structure of the lactone that yields L-galactose.

- Use the wedge/hash bond tools to indicate stereochemistry.

- You do not have to explicitly draw H atoms.

- If a group is achiral, do not use wedged or hashed bonds on it.

- Do not include lone pairs in your answer. They will not be considered in the grading.

Answer 1