Q17 · CSIR-NET Chemistry, December 2012
Paper: CSIR-NET December 2012 · Subject: Organic Chemistry · Chapter: Natural Products · Topic: Carbohydrates · Marks: 2 · Difficulty: Medium
Under review — part of this question (a structure or an option) is not clear in the source scan. 4AB is checking it against the original book; the answer shown may change.
The osazone A could be obtained from 
(a)Glucose and mannose
(b)Mannose and galactose
(c)Glucose and fructose
(d)Galactose and fructose
Answer
Under review — not yet confirmed.
Answer: A
Answer: Glucose, mannose and fructose — options (a) and (c).
Explanation
Answer: Glucose, mannose and fructose — options (a) and (c) — The osazone has the D-arabino configuration at C-3, C-4 and C-5. Osazone formation destroys the C-1/C-2 difference, so D-glucose, D-mannose (the C-2 epimer) and D-fructose all give this same osazone; galactose does not.
Study loop for Natural Products