How can you find out the presence of primary alcoholic group in glucose?
Answers
Glucose gives a penta ester with acetic anhydride, revealing that it has 5 hydroxyl groups. On oxidation with Nitric acid (HNO3),glucose as well as gluconic acid both yeild a dicarboxylic acid (saccharic acid). This indicates the presence of a primary alcoholic group in glucose.
Answer:
Explanation:
To prove the presence of -CHO group:
When glucose reacts with hydroxylamine, oxime is formed and cyanohydrins are formed on the addition of hydrogen cyanide to it. This reaction can confirm the presence of carbonyl group in glucose. And also on the reaction of glucose with a mild oxidising agent like bromine water, the glucose gets oxidised to carboxylic acid containing six carbon atoms. This indicates that the carbonyl group is present (as an aldehyde group).
To prove the presence of -OH groups:
The presence of -OH group is confirmed after the acetylation of glucose with acetic acid which gives glucose pentaacetate.
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