Enantiomers are isomers that are mirror images of each other, a concept dealt with in detail
in E15. Vitamin C is the L-enantiomer of ascorbic acid, as shown in Figure 1. (See Skill
13 if you can’t understand the stick structures used.) Ascorbic acid is a stable solid that
does not react with air, however, it is rapidly oxidised on exposure to air and light when in
aqueous solution. The product of this oxidation is dehydroascorbic acid