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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
Draw the simple Fisher projection formulae of D - (+) - glucose and D - (-) - fructose
What happens when glucose is treated with hydroxylamine?
Glucose on reaction with HI gives n-hexane. What does it suggest about the structure of glucose?
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.
Write the reactions involved when D-glucose is treated with the following reagent:
H2N-OH
The following compound can be called as:
The spatial arrangement of the given molecule is denoted by:
Choose the appropriate answer(s) for the below representation from the options given
Which is the least stable form of glucose?
A solution of D-glucose in water rotates the plane polarised light ____________.
The α-D glucose and β-D glucose differ from each other due to difference in carbon atom with respect to its ____________.
Choose the correct relationship for glucose and fructose:
Which one of the following reactions is not explained by the open chain Structure of glucose?
How will you distinguish 1° and 2° hydroxyl groups present in glucose? Explain with reactions.
Account for the following:
What happens when D – glucose is treated with the following reagents
HNO3
When D-glucose reacts with HI, it forms ______.
The reagents with which glucose does not react to give the corresponding tests/products are:
- Tollen’s reagent
- Schiff’s reagent
- HCN
- NH2OH
- NaHSO3
Choose the correct options from the given below:
