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प्रश्न
How are the following compounds prepared?
benzaldehyde from benzene
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उत्तर
(a) Benzaldehyde from benzene
Benzene
Gatterman Koch synthesis
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संबंधित प्रश्न
Arrange the following compound in increasing order of its reactivity in nucleophilic addition reactions.
Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone.
Hint: Consider steric effect and electronic effect.
What is meant by the following term? Give an example of the reaction in the following case.
Acetal
What is meant by the following term? Give an example of the reaction in the following case.
Hemiacetal
What is meant by the following term? Give an example of the reaction in the following case.
Oxime
Predict the products formed when cyclohexanecarbaldehyde reacts with the following reagents.
Excess ethanol and acid
How will you bring about the following conversion in not more than two steps?
Bromobenzene to 1-Phenylethanol
Give plausible explanation for the following:
Cyclohexanone forms cyanohydrin in good yield but 2, 2, 6 trimethylcyclohexanone does not.
Give plausible explanation for the following:
There are two −NH2 groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
Complete the synthesis by giving missing starting material, reagent or product.
\[\ce{C6H5CHO ->[H2NCONHNH2]}\]
Write balanced chemical equations for action of ammonia on - acetone
Write balanced chemical equations for action of ammonia on - acetone
What is the action of the following reagents on ethanoic acid?
1) `LiAlH_4"/"H_3O^+`
2) `PCl_3 , "heat"`
3) `P_2O_5, "heat"`
Grignard reagent on reaction with acetone forms.
Paraldehyde is formed as a result of polymerisation:-
Which among the following is most reactive to give nucleophilic addition?
What is the action of sodium hypoiodite on acetone?
Arrange the following in the increasing order of their property indicated:
Ethanal, Propanone, Propanal, Butanone (reactivity towards nucleophilic addition)
The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
| The carbon-oxygen double bond is polarised in aldehydes and ketones due to higher electronegativity of oxygen relative to carbon. Therefore, they undergo nucleophilic addition reactions with a number of nucleophiles such as HCN, NaHSO3, alcohols, ammonia derivatives and Grignard reagents. Aldehydes are easily oxidised by mild oxidising agents as compared to ketones. The carbonyl group of carboxylic acid does not give reactions of aldehydes and ketones. Carboxylic acids are considerably more acidic than alcohols and most of simple phenols. |
Answer the following:
(a) Write the name of the product when an aldehyde reacts with excess alcohol in the presence of dry HCl. (1)
(b) Why carboxylic acid is a stronger acid than phenol? (1)
(c) (i) Arrange the following compounds in increasing order of their reactivity towards CH3MgBr: (1)
CH3CHO, \[\begin{array}{cc}
\ce{(CH3)3C-C-CH3}\\
\phantom{....}||\\
\phantom{....}\ce{O}
\end{array}\], \[\begin{array}{cc}
\ce{CH3-C-CH3}\\
||\\
\ce{O}
\end{array}\]
(ii) Write a chemical test to distinguish between propanal and propanone. (1)
OR
(c) Write the main product in the following: (2)
| (i) |  |
| (ii) |  |
Write the structure of the product formed when acetone reacts with 2, 4 DNP reagent.
Draw structures of the given derivatives.
The ethylene ketal of hexan-3-one
Draw structure of the following derivative.
The ethylene ketal of hexan-3-one
Draw structure of the following derivative.
The ethylene ketal of hexan-3-one
Draw structures of the following derivatives.
Acetaldehydedimethylacetal
Draw structures of the given derivatives.
The ethylene ketal of hexan-3-one
