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कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान 2nd PUC Class 12

How will you convert ethanal into the following compound? But-2-enal - Chemistry

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प्रश्न

How will you convert ethanal into the following compound?

But-2-enal

Carry out the following conversion: 

Ethanal to But-2-enal

How will you bring about the following conversion?

Ethanal to but-2-enal

रासायनिक समीकरणे/रचना
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उत्तर १

\[\ce{\underset{Ethanal}{2CH3CHO}->[(i) dil.NaOH][(ii) H+, \Delta]\underset{But-2-enal}{CH3CH = CHCHO}}\]

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उत्तर २

\[\ce{\underset{Ethanal}{2CH3CHO}->[dil.NaOH][Aldol condensation]\underset{Hydroxybutanal}{\overset{4}{C}H3 - \overset{3}{C}HOH - \overset{2}{C}H2 - \overset{1}{C}HO}->[H3O+/\Delta][-H2O]\underset{But-2-enal}{CH3 - CH = CH - CHO}}\]

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  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 8: Aldehydes, Ketones and Carboxylic Acids - Exercises [पृष्ठ २५६]

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एनसीईआरटी Chemistry Part 1 and 2 [English] Class 12
पाठ 8 Aldehydes, Ketones and Carboxylic Acids
Exercises | Q 8.8 (ii) | पृष्ठ २५६

संबंधित प्रश्‍न

What is meant by the following term? Give an example of the reaction in the following case.

Aldol


Write structural formulas and names of four possible aldol condensation products from propanal and butanal. In each case, indicate which aldehyde acts as nucleophile and which as electrophile.


Complete the synthesis by giving missing starting material, reagent or product.

\[\begin{array}{cc}
\ce{C6H5CHO}\phantom{............}\\
\phantom{........}\ce{+\phantom{......}\ce{->[dil.NaOH][\Delta]}}\phantom{...}\\
\ce{CH3CH2CHO}\phantom{............}
\end{array}\]


Give reasons  Acetylation of aniline reduces its activation effect.


Write chemical equations of the following reaction : 

Propanone is treated with dilute Ba (OH)2-.


Write chemical equations of the following reaction :
Benzoyl chloride is hydrogenated in the presence of `"Pd"/(BaSO_4)`


What is substituted imine called?


Cannizaro’s reaction is not given by ______.


Compounds A and C in the following reaction are:

\[\ce{CH3CHO ->[(i) CH3MgBr][(ii) H2O] (A) ->[H2SO4, Δ] (B) ->[Hydroboration oxidation] (C)}\]


Compound ‘A’ was prepared by oxidation of compound ‘B’ with alkaline \[\ce{KMnO4}\]. Compound ‘A’ on reduction with lithium aluminium hydride gets converted back to compound ‘B’. When compound ‘A’ is heated with compound B in the presence of \[\ce{H2SO4}\] it produces fruity smell of compound C to which family the compounds ‘A’, ‘B’ and ‘C’ belong to?


Why are carboxylic acids more acidic than alcohols or phenols although all of them have hydrogen atom attached to a oxygen atom \[\ce{(-O-H)}\]?


Assertion: The α-hydrogen atom in carbonyl compounds is less acidic.

Reason: The anion formed after the loss of α-hydrogen atom is resonance stabilised.


When liquid ‘A’ is treated with a freshly prepared ammoniacal silver nitrate solution, it gives bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid ‘B’ also forms a white crystalline solid with sodium hydrogensulphite but it does not give test with ammoniacal silver nitrate. Which of the two liquids is aldehyde? Write the chemical equations of these reactions also.


Give reasons to support the answer:

Presence of Alpha hydrogen in aldehydes and ketones is essential for aldol condensation.


Cross aldol condensation occurs between


Which of the following gives aldol con~ensation reaction?


Identify A and B from the following reaction:

\[\begin{array}{cc}
\ce{CH3}\phantom{.................}\\
|\phantom{....................}\\
\phantom{}\ce{2CH3 - C = O ->[Ba(OH)2] A ->[Δ] B + H2O}
\end{array}\]


Which of the following compounds will undergo self-condensation in the presence of dilute NaOH solution?


When acetaldehyde is treated with dilute NaOH, the following reaction is observed.

\[\begin{array}{cc}
\ce{2CH3 - CHO ->[dil.NaOH] CH3 - CH - CH2 - CHO}\\
\phantom{...............}|\\
\phantom{.................}\ce{OH}
\end{array}\]

  1. What are the functional groups in the product?
  2. Can another product be formed during the same reaction? (Deduce the answer by doing atomic audit of reactant and product).
  3. Is this an addition reaction or condensation reaction?

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