Question

For D-arabinose:

1. Draw its enantiomer.
2. Draw an epimer at C3.
3. Draw a diastereomer that is not an epimer.
4. Draw a constitutional isomer that still contains a carbonyl group.

Short answer

Answer

a.

b.

c.

d.

Step-by-step solution

Epimers

Epimers in stereochemistry are formed by swapping the groups at one or more stereocenters.From enantiomers, we get mirror images, and in the case of diastereomers, no mirror images are formed.

Enantiomer of D-arabinose

a. D-arabinose's enantiomer is drawn by swapping the groups (H and OH) attached to the three stereocenters of D-arabinose.

Enantiomer of D-arabinose

Epimer at C3

b. The epimer at C3 of D-arabinose is drawn by swapping the groups (H and OH) attached at C3 carbon.

Epimer at C3

Diastereomer that is not an epimer.

c. Diastereomer of D-arabinose is drawn so that it is not a mirror image of D-arabinose

Diastereomer of D-arabinose

Constitutional isomer that still contains a carbonyl group.

d. A constitutional isomer of D-arabinose is drawn by changing the bonding patterns but keeping the same chemical formula.

Constitutional isomer of D-arabinose