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

How will you bring about the following conversion in not more than two steps? Ethanol to 3-Hydroxybutanal

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प्रश्न

How will you bring about the following conversion in not more than two steps?

Ethanol to 3-Hydroxybutanal

How will you convert the following:

Ethanol to 3-Hydroxybutanal

रासायनिक समीकरणे/रचना
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उत्तर १

\[\begin{array}{cc}
\phantom{...............................................................}\ce{OH}\\
\phantom{.............................................................}|\\
\ce{\underset{Ethanal}{CH3 - CH2 - OH}->[Mild oxidation][KMnO4/dil.H2SO4]\underset{(Two molecules)}{\underset{Acetaldehyde}{CH3 - CHO}}->[dil.OH-][warm]\underset{3-Hydroxybutanal}{CHO - CH2 - CH - CH3}}\
\end{array}\]

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उत्तर २

\[\begin{array}{cc}
\phantom{....................................}\ce{OH}\\
\phantom{..................................}|\\
\ce{CH3CH2OH ->[PCC] CH3CHO ->[dil NaOH][Aldol condensation] \underset{3-Hydroxybutanal}{CH3 - CH - CH2 - CHO}}
\end{array}\]

PCC = Pyridinechlorochromate

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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 8.15 (iii) | पृष्ठ २५६

संबंधित प्रश्‍न

Write the products formed when CH3CHO reacts with the following reagents: CH3CHO in the presence of dilute NaOH


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

Aldol


Which of the following compounds would undergo aldol condensation, which the Cannizzaro reaction and which neither? Write the structures of the expected products of aldol condensation and Cannizzaro reaction.

  1. Methanal
  2. 2-Methylpentanal
  3. Benzaldehyde
  4. Benzophenone
  5. Cyclohexanone
  6. 1-Phenylpropanone
  7. Phenylacetaldehyde
  8. Butan-1-ol
  9. 2, 2-Dimethylbutanal

How will you convert ethanal into the following compound?

Butane-1, 3-diol


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.


Cannizaro’s reaction is not given by ______.


Compounds A and C in the following reaction are:

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


Which of the following compounds do not undergo aldol condensation?

(i) \[\ce{CH3 - CHO}\]

(ii)  

(iii)  \[\begin{array}{cc}
\phantom{}\ce{O}\\
\phantom{}||\\
\ce{CH3 - C - CH3}
\end{array}\]

(iv) \[\begin{array}{cc}
\phantom{}\ce{CH3}\\
|\phantom{...}\\
\ce{CH3 - C - CHO}\phantom{..}\\
|\phantom{...}\\
\phantom{}\ce{CH3}\\
\end{array}\]


Why is there a large difference in the boiling points of butanal and butan-1-ol?


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.


Which of the following gives aldol con~ensation reaction?


Identify A and B from the following reaction:

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


Explain the aldol condensation of ethanal.


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


Write a note on the aldol condensation reaction of acetaldehyde.


What is aldol condensation? Explain it with suitable examples.


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