JEE Main levelOne or more correct optionsDifficulty 2 of 3bm173
Which of the following pairs of sugars give the same osazone with excess phenylhydrazine?
AD-glucose and D-fructose
BD-glucose and D-mannose
CD-glucose and D-galactose
DD-mannose and D-fructose
Answer: A, B, D
Osazone formation uses C-1 and C-2 only, so sugars that have identical configuration at C-3, C-4 and C-5 give the same osazone. Glucose, mannose and fructose share C-3 to C-5; galactose differs at C-4, so it gives a different osazone.