Question
What will happen when $$D - \left( + \right) - $$ glucose is treated with methanolic $$-HCl$$ followed by Tollens’ reagent ?
A.
A black $$ppt.$$ will be formed
B.
A red $$ppt.$$ will be formed
C.
A green colour will appear
D.
No characteristic colour or $$ppt.$$ will be formed.
Answer :
No characteristic colour or $$ppt.$$ will be formed.
Solution :
Reaction of $$D - \left( + \right) - $$ glucose with methanolic $$-HCl$$ leads to formation of methyl glucoside ( $${C_1} - OH$$ group is methylated ) which, being acetal, is not hydrolysable by base, so it will not respond Tollen’s reagent.