Question

Why the answer is D?

(I think the two epimers have opposite configuration at only "one" stereogenic cente.)

33. The two monosaccharides shown below could BEST be described as: но но не но-ф-н н-с-он) но-с-н но-с-н но-с-н н–с-он н–с-он сн,он сн,он A) ketoses. B) anomers. C) rotamers. D) еріmеrѕ. E) enantiomers.

Answer 1

The structure on right side is of D-Idose. The enantiomer of D-Idose is L-Idose. This L-Idose is an epimer of D-Glucose at carbon no. 5. Another structure on left side is of Galactose which is an epimer of Glucose with difference on carbon number 4. So , these structures can be best described as epimers.

нс - он НО-С-н н— — но-— H cң, он L-Idose