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प्रश्न
Write the reactions of D-glucose which can’t be explained by its open-chain structure. How can cyclic structure of glucose explain these reactions?
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उत्तर
Following reactions and facts could not be explained by open-chain structures of glucose.
• Despite having the aldehyde group, glucose does not give 2, 4 − DNP test, Schiff's test and it does not form the hydrogen sulphide addition product with \[\ce{NaHSO3}\].
• The pentaacetate of glucose does not react with hydroxylamine indicating the absence of a free −CHO group.
It was proposed that one of the −OH groups may add to the −CHO group and form a cyclic hemiacetal structure. It was found that glucose forms a six-membered ring in which −OH at C − 5 is involved in a ring formation.
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संबंधित प्रश्न
Write the reaction that indicates the presence of -CHO group in glucose
What happens when glucose is treated with hydroxylamine?
Enlist the properties of glucose that can not be explained on the basis of open chain structure of it
Write the product when D-glucose reacts with conc. HNO3.
Differentiable between the following:
Amylose and Amylopectin
What do you observe when glucose solution is heated with Tollen’s reagent?
Fill in the blanks by choosing the appropriate word/words from those given in the brackets:
(iodoform, acetaldehyde, positive, greater, acidic, acetone, disaccharide, negative, increases, glucose, decreases, chloroform, polysaccharide, lactose, lesser, basic, cationic hydrolysis, anionic hydrolysis)
Sucrose is a _________ and yields upon hydrolysis, a mixture of ________ and fructose.
What do you observe when glucose is treated with bromine water?
Write the reaction involved when D-glucose is treated with the following reagent:
Br2 water
The following compound can be called as:
The symbols D and L represents ____________.
The number of chiral carbon atoms present in cyclic structure α-D(+) glucose:
Choose the correct relationship for glucose and fructose:
The number of chiral carbons in ß-D(+) glucose is ____________.
In the following reaction, identify A and B:
\[\begin{array}{cc}
\ce{C6H12O6 ->[Acetic anhydride] A}\\
\downarrow \text{Conc. nitric acid}\phantom{...}\\
\ce{B}\phantom{.................}\end{array}\]
Three structures are given below in which two glucose units are linked. Which of these linkages between glucose units are between C1 and C4 and which linkages are between C1 and C6?
| (I) |  |
| (II) |  |
| (III) |  |
What happens when D-glucose is treated with the following reagent?
HI
Account for the following:
What happens when D – glucose is treated with the following reagents
Bromine water
Account for the following:
What happens when D – glucose is treated with the following reagents
HNO3
