Consider the structures below.Which of the structures II-VI are epimers of I?

Question

Quizplus · Accepted Answer

Epimers are two sugars that differ only in the configuration around one carbon atom. In this case, structure I is D-galactose. Structure II is an aldose that has the same configuration as D-galactose at all carbons except carbon 4, where it has an OH group instead of an H. Structures III and IV are epimers of each other because they differ only in the configuration of the hydroxyl group on carbon 2 (galactose has an OH group while glucose has an H). Structure V is an aldose that has the same configuration as D-galactose at all carbons except carbon 5, where it has an OH group instead of an H. Structure VI is an aldose that has the same configuration as D-galactose at all carbons except carbon 6, where it has an OH group instead of an H. Therefore, structures III and IV are epimers of I, and structures II, V, and VI are not.

Consider the Structures Below