Answer to Question #212570 in Organic Chemistry for Mahnoor

Question

1.     Glucose and Fructose belongs to the carbohydrate family but they react differently, which functional group makes them different from one another and how would you distinguish them by giving simple chemical test?                                                                          (03)

Answer 1

Since fructose has a ketone functional group, the ring closure occurs at carbon # 2. In the case of fructose a five membered ring is formed. The -OH on carbon #5 is converted into the ether linkage to close the ring with carbon #2. This makes a 5 member ring - four carbons and one oxygen.