Fructose contains a keto group but still it reduces Tollen's reagent. Explain.

Explanation

Under the basic conditions of Tollens' reagent , fructose undergoes Lobry de Bruyn van Eikenstein rearrangement (refer to ' Supplement Your Knowledge for Competitions '). As a result, fructose gives a equilibrium mixture of fructose and mannose . Since both glucose and mannose contain `-CHO` group , therefore , they reduce Tollen's reagent.