JEE Main · 2022 · Shift-ImediumBIO-023

A sugar 'X' dehydrates very slowly under acidic condition to give furfural which on further reaction with resorcinol…

Biomolecules · Class 12 · JEE Main Previous Year Question

Question

A sugar 'X' dehydrates very slowly under acidic condition to give furfural which on further reaction with resorcinol gives the coloured product after sometime. Sugar 'X' is

Options
  1. a

    Aldopentose

  2. b

    Aldotetrose

  3. c

    Oxalic acid

  4. d

    Ketotetrose

Correct Answera

Aldopentose

Detailed Solution

Step 1: Furfural Formation — Furfural is formed by the acid-catalyzed dehydration of pentoses (five-carbon sugars).

Step 2: Identifying the Sugar Type — Aldopentoses dehydrate slowly to furfural, whereas ketopentoses react much faster in similar tests (like Seliwanoff’s\text{Seliwanoff's}).

Step 3: Conclusion — Since 'X' is a pentose that forms furfural slowly, it is classified as an aldopentose.

Key Point: Furfural derivatives are common intermediates in various qualitative tests for carbohydrates.

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A sugar 'X' dehydrates very slowly under acidic condition to give furfural which on further… (JEE Main 2022) | Canvas Classes