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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
उत्तर १
\[\begin{array}{cc}
\phantom{...............................................................}\ce{OH}\\
\phantom{.............................................................}|\\
\ce{\underset{Ethanal}{CH3 - CH2 - OH}->[Mild oxidation][KMnO4/dil.H2SO4]\underset{(Two molecules)}{\underset{Acetaldehyde}{CH3 - CHO}}->[dil.OH-][warm]\underset{3-Hydroxybutanal}{CHO - CH2 - CH - CH3}}\
\end{array}\]
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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संबंधित प्रश्न
What is meant by the following term? Give an example of the reaction in the following case.
Aldol
How will you convert ethanal into the following compound?
Butane-1, 3-diol
Describe the following:
Cross aldol condensation
Write chemical equations of the following reaction :
Benzoyl chloride is hydrogenated in the presence of `"Pd"/(BaSO_4)`
Which product is formed when the compound 
is treated with concentrated aqueous \[\ce{KOH}\] solution?
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?
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.
Give reasons to support the answer:
Presence of Alpha hydrogen in aldehydes and ketones is essential for aldol condensation.
Convert the following:
Acetaldehyde to But-2-enal
Predict the reagent for carrying out the following transformations:
Ethanal to 3-hydroxy butanal
The major product of the following reaction is:
Write a note on the aldol condensation reaction of acetaldehyde.
What is aldol condensation? Explain it with suitable examples.
