How will you convert ethanal into the following compounds? (i) Butane-1,3-diol (ii) But-2-enal (iii) But-2-enoic acid
Ethanal undergoes aldol condensation in the presence of dilute alkali to form 3-hydroxybutanal, which on reduction with NaBH₄ gives Butane-1,3-diol.
Ethanal undergoes aldol condensation followed by dehydration on heating to form But-2-enal.
Ethanal undergoes aldol condensation followed by dehydration to form But-2-enal, which on oxidation with mild oxidising agents like AgNO₃ (Tollens' reagent) gives But-2-enoic acid.
Explanation
The context mentions aldol condensation in Question 8.7, indicating that ethanal (which has α-hydrogens) can undergo aldol condensation. The aldol product from ethanal is 3-hydroxybutanal. This intermediate can be: (i) reduced to form Butane-1,3-diol, (ii) dehydrated to form But-2-enal, or (iii) further oxidised to form But-2-enoic acid. The context also shows oxidation reactions using reagents like Tollens' reagent (Ammoniacal AgNO₃) for converting aldehydes to acids.