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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.
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उत्तर १
\[\ce{\underset{Ethanal}{2CH3CHO}->[(i) dil.NaOH][(ii) H+, \Delta]\underset{But-2-enal}{CH3CH = CHCHO}}\]
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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संबंधित प्रश्न
What is meant by the following term? Give an example of the reaction in the following case.
Aldol
How will you bring about the following conversion in not more than two steps?
Ethanol to 3-Hydroxybutanal
Describe the following:
Cross aldol condensation
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-.
What is substituted imine called?
Which product is formed when the compound 
is treated with concentrated aqueous \[\ce{KOH}\] solution?
Why is there a large difference in the boiling points of butanal and butan-1-ol?
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?
Assertion: Aromatic aldehydes and formaldehyde undergo Cannizaro reaction.
Reason: Aromatic aldehydes are almost as reactive as formaldehyde.
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.
Identify A and B from the following reaction:
\[\begin{array}{cc}
\ce{CH3}\phantom{.................}\\
|\phantom{....................}\\
\phantom{}\ce{2CH3 - C = O ->[Ba(OH)2] A ->[Δ] B + H2O}
\end{array}\]
The major product of the following reaction is:
Assertion (A): The final product in Aldol condensation is always α, β-unsaturated carbonyl compound.
Reason (R): α, β-unsaturated carbonyl compounds are stabilised due to conjugation.
Identify A and B:
Write a note on the aldol condensation reaction of acetaldehyde.
What is aldol condensation? Explain it with suitable examples.
