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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
Acetaldehyde, when treated with which among the following reagents does NOT undergo addition reaction?
(A) Ammonia
(B) Hydroxylamine
(C) Ammoniacal silver nitrate
(D) Semicarbazide
Arrange the following in the increasing order of their reactivity towards nucleophilic addition reaction:
C6H5COCH3, CH3-CHO, CH3COCH3
Draw the structure of the semicarbazone of ethanal.
Write the products formed when CH3CHO reacts with the following reagents : H2N – OH
What is meant by the following term? Give an example of the reaction in the following case.
Hemiacetal
Predict the products formed when cyclohexanecarbaldehyde reacts with the following reagents.
PhMgBr and then H3O+
Predict the products formed when cyclohexanecarbaldehyde reacts with the following reagents.
Semicarbazide and weak acid
Acetaldehyde, Acetone, Di-tert-butyl ketone, Methyl tert-butyl ketone (reactivity towards HCN)
Explain the mechanism of alkaline hydrolysis of tert-butyl bromide with energy profile diagram.
How are the following compounds prepared?
acetophenone from benzene
Acetone, Acetaldehyde, Benzaldehyde, Acetophenone – reactivity towards addition of HCN.
How will you convert benzoic acid to m-bromobenzoic acid?
Identify the compounds A, B and C in the following reaction.
\[\ce{CH3 - Br ->[Mg/ether] (A) ->[(i) CO][(ii) Water] (B) ->[CH3OH/H+][Δ] (C)}\]
A Idol condensation will not be observed in
The most stable reagent for the conversion of R – CH2OH → RCHO is
Which among the following is most reactive to give nucleophilic addition?
What happens when propanone is treated with CH3MgBr and then hydrolysed?
In the following reaction
\[\ce{Carbonyl compound + MeOH <=>[HCl] acetal}\]
Rate of the reaction is the highest for ______.
The product of following reaction is
\[\ce{CH3 - CH = CH - CH2 - CHO ->[i) LiAlH4][ii) H3O+]}\] ______?
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) |  |
Out of p-tolualdehyde and p-nitrobenzaldehyde, which one is more reactive towards nucleophilic addition reactions, why?
Draw structure of the following derivative.
The ethylene ketal of hexane-3-one
Draw structures of the following derivative.
The ethylene ketal of hexan-3-one
Draw the structure of the following derivative.
Acetaldehydedimethylacetal
Draw the structure of the following derivative.
The ethylene ketal of hexan-3-one
Draw structures of the following derivatives.
Acetaldehydedimethylacetal
Draw the structure of the given derivative.
The ethylene ketal of hexan-3-one
Give an example of the reaction in the following case.
Oxime
The major product of the following reaction is:
