Question

Why the fifth oxgen is taken to make cyclic glucose

Answer 1

Answer:

Glucose includes an aldehyde group with an electrophilic carbon. ... Take a look at the linear form of glucose below. If the OH group on C-4 adds to the aldehyde carbon it will make a 5-membered ring, and if the OH group on C-5 adds to C-1 it will make ... Both of the electrons are donated from the nucleophilic oxygen atom.