Aldehydes and K...

One or More than One Options Correct Type

Direction (Q. Nos. 1-4) This section contains 4 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.

Q. 

 What is/are expected product(s) in the following reaction?

Which of the following form enamine on heating with a secondary amine in weakly acidic medium ?

The compound(s) which form a pair of diastereomers with hydroxylamine is/are

The compound(s) below that gives yellow precipitate with KOH/I₂ is/are

Comprehension Type

Direction : This section contains a paragraph, describing theory, experiments, data, etc. Three questions related to the paragraph have been given. Each question has only one correct answer among the four given options (a), (b), (c) and (d).

Passage

Aidehydes and ketones react with ammonia and primary amines to form imines in slightly acidic condition. A typical reaction mechanism with a primary amine is as follows

The proper pH control is crucial to imine formation otherwise reaction does not proceed at appreciable rate.
However, if a secondary amine is reacted, no hydrogen is left on nitrogen on intermediate (I) for the deprotonation in step II. Hence, the reaction proceeds as

Enamine is a suitable intermediate route for α-alkyiation of a carbonyl compound.

Q. 

What happens if imine form ation is carried out at very low pH?

Aidehydes and ketones react with ammonia and primary amines to form imines in slightly acidic condition. A typical reaction mechanism with a primary amine is as follows

The proper pH control is crucial to imine formation otherwise reaction does not proceed at appreciable rate.
However, if a secondary amine is reacted, no hydrogen is left on nitrogen on intermediate (I) for the deprotonation in step II. Hence, the reaction proceeds as

Enamine is a suitable intermediate route for α-alkyiation of a carbonyl compound.

Q. 

Which of the following is expected to give more than one imine when treated with CH₃ NH₂ ?

Aidehydes and ketones react with ammonia and primary amines to form imines in slightly acidic condition. A typical reaction mechanism with a primary amine is as follows

The proper pH control is crucial to imine formation otherwise reaction does not proceed at appreciable rate.
However, if a secondary amine is reacted, no hydrogen is left on nitrogen on intermediate (I) for the deprotonation in step II. Hence, the reaction proceeds as

Enamine is a suitable intermediate route for α-alkyiation of a carbonyl compound.

Q. 

What is the product X in the following reaction?

One Integer Value Correct Type

Direction : This section contains 4 questions. When worked out will result in an integer from 0 to 9 (both inclusive).

Q. 

 In the following reaction, how many isomers of trioximes are formed?

Consider the isomeric aldehydes with molar mass 100, if all the isomers (only structural) are treated independently with NH₂ OH, how many of them would give more than two stereomeric oximes?

When formaldehyde reacts with ammonia, a typical compound called hexamethylene tetramine is formed. How many six membered rings are present in this compound?

The smallest acyclic ketone that gives pair of diastereomers with CH₃ NH₂ in slightly acidic medium has how many carbon atoms?