Draw the structure of ascorbic acid and identify the functional groups present

Here is the structure of ascorbic acid (Vitamin C) and its functional groups:

Ascorbic acid has a five-membered ring containing an enediol group, and a furanose ring.

• The structure contains a lactone (cyclic ester) group.
• It has two hydroxyl groups attached to the ring.
• It also has an enediol group, which is a double bond between two carbons, each bearing a hydroxyl group. This enediol is part of an α,β-unsaturated carbonyl system.

      O
     //
HO--C
    |
HO--C
    |
    C=C--OH
   /   \
  CH₂   OH
  |
  O