Advertisements
Advertisements
Question
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.
Advertisements
Solution
The possible products of aldol condensation from propanal and butanal are:
(i) \[\begin{array}{cc}
\phantom{..............................}\ce{OH}\phantom{...}\ce{CH3}\\
\phantom{...........................}|\phantom{.....}|\\
\ce{\underset{Propanal}{2CH3CH2CHO}->[dil.\overset{-}{O}H]\underset{3-Hydroxy-2-methylpentanal}{H3C - CH2 - CH - CH - CHO}}\\
\end{array}\]
(ii) \[\begin{array}{cc}
\phantom{.......................................}\ce{OH}\phantom{..}\ce{CH2CH3}\\
\phantom{................................}|\phantom{.....}|\\
\ce{\underset{Butanal}{2CH3(CH2)2CHO}->[dil.\overset{-}{O}H]\underset{2-Ethyl-3-hydroxyhexanal}{H3C - (CH2)2 - CH - CH - CHO}}\
\end{array}\]
(iii) When butanal acts as an electrophile and propanal as a nucleophile:
\[\begin{array}{cc}
\phantom{...........................................}\ce{OH}\\
\phantom{.........................................}|\\
\ce{\underset{Butanal}{H3C - (CH2)2CHO} + \underset{Propanal}{CH3CH2CHO}->[\overset{-}{O}H]H3C - (CH2)2 - CH - CH - CHO}\\
\phantom{.....................................................}|\\
\phantom{.........................................................}\ce{\underset{3-Hydroxy-2-methylhexanal}{CH3}}\
\end{array}\]
(iv) When propanal serves as an electrophile and butanal as a nucleophile:
\[\begin{array}{cc}
\phantom{............................................}\ce{OH}\phantom{...}\ce{C2H5}\\
\phantom{.........................................}|\phantom{......}|\\
\ce{CH3CH2CHO + CH3(CH2)2CHO -> \underset{2-Ethyl-3-hydroxypentanal}{H3C - CH2 - CH - CH - CHO}}\
\end{array}\]
APPEARS IN
RELATED QUESTIONS
How will you convert ethanal into the following compound?
Butane-1, 3-diol
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 a chemical equation for the following reaction:
Propanone is treated with dilute Ba( OH)2.
Explain aldol condensation reaction in detail.
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 conversions can be carried out by Clemmensen Reduction?
(i) Benzaldehyde into benzyl alcohol
(ii) Cyclohexanone into cyclohexane
(iii) Benzoyl chloride into benzaldehyde
(iv) Benzophenone into diphenyl methane
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?
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?
Which of the following does not give aldol condensation reaction?
Why is the α-hydrogens of aldehydes and ketones are acidic in nature?
Identify A and B:
When acetaldehyde is treated with dilute NaOH, the following reaction is observed.
\[\begin{array}{cc}
\ce{2CH3 - CHO ->[dil.NaOH] CH3 - CH - CH2 - CHO}\\
\phantom{...............}|\\
\phantom{.................}\ce{OH}
\end{array}\]
- What are the functional groups in the product?
- Can another product be formed during the same reaction? (Deduce the answer by doing atomic audit of reactant and product).
- Is this an addition reaction or condensation reaction?
Write a note on the aldol condensation reaction of acetaldehyde.
Which one of the following undergoes reaction with 50% sodiumhydroxide solution to give the corresponding alcohol and acid:
