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प्रश्न
Account for the following:
There are 5 OH groups in glucose
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उत्तर
Acetylation of glucose with acetic anhydride gives glucose pentaacetate which confirms the presence of five –OH groups. Since it exists as a stable compound, five –OH groups should be attached to different carbon atoms.
\[\begin{array}{cc}
\phantom{...}\ce{CHO}\phantom{...................}\ce{CHO}\phantom{....}\phantom{}\ce{O}\phantom{.........}\\
\phantom{..}|\phantom{.......................}|\phantom{}\phantom{........}||\phantom{........}\\
\phantom{}\ce{(CHOH)4 ->[Acetic anhydride] (CH-O-C-CH3)4}\\
\phantom{..........................}\ce{O}\\
\phantom{..}|\phantom{.......................}|\phantom{.}\phantom{........}||\phantom{........}\\
\phantom{}\ce{CH2OH}\phantom{................}\ce{CH2-O-C-CH3}\phantom{}
\end{array}\]
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संबंधित प्रश्न
Write the reaction that indicates the presence of -CHO group in glucose
Enumerate the reactions of D-glucose which cannot be explained by its open chain structure.
What happens when glucose is treated with hydroxylamine?
The following compound can be called as:
Which of the following reactions of glucose can be explained only by its cyclic structure?
The number of chiral carbons in ß-D(+) glucose is ____________.
On the basis of which evidences D-glucose was assigned the following structure?
\[\begin{array}{cc}
\ce{CHO}\\
|\phantom{....}\\
\phantom{..}\ce{(CHOH)4}\\
|\phantom{....}\\
\phantom{..}\ce{CH2OH}
\end{array}\]
Account for the following:
What happens when D – glucose is treated with the following reagents
Bromine water
Consider the following reactions:
(i) \[\ce{Glucose + R-OH ->[Conc. HNO3] [A] ->[X eq of][(CH3CO)2O] Acetyl derivative}\]
(ii) \[\ce{Glucose ->[Ni/H2] [A] ->[Y eq of][(CH3CO)2O] Acetyl derivative}\]
(iii) \[\ce{Glucose ->[Z eq of][(CH3CO)2O] Acetyl derivative}\]
'X, 'Y' and 'Z' in these reactions are respectively:
Give a reason for the following observations:
Penta-acetate of glucose does not react with hydroxylamine.
