Question

Draw a structural formula of the principal product formed when ethyl benzoate is treated with each reagent. (a) \(\mathrm{H}_{2} \mathrm{O}, \mathrm{NaOH}\), heat (b) \(\mathrm{H}_{2} \mathrm{O}, \mathrm{H}_{2} \mathrm{SO}_{4}\), heat (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}\) (d) DIBALH \(\left(-78^{\circ} \mathrm{C}\right)\), then \(\mathrm{H}_{2} \mathrm{O}\) (e) \(\mathrm{LiAlH}_{4}\), then \(\mathrm{H}_{2} \mathrm{O}\) (f) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{MgBr}\) (two equivalents), then \(\mathrm{HCl} / \mathrm{H}_{2} \mathrm{O}\)

Short answer

Question: Draw the structural formula for the principal product formed in each reaction of ethyl benzoate with the given reagents. a) Ethyl benzoate + H2O, NaOH, heat b) Ethyl benzoate + H2O, H2SO4, heat c) Ethyl benzoate + CH3CH2CH2CH2NH2 d) Ethyl benzoate + DIBALH (-78°C), then H2O e) Ethyl benzoate + LiAlH4, then H2O f) Ethyl benzoate + C6H5MgBr (two equivalents), then HCl/H2O

Step-by-step solution

Hydrolysis of ester

Ethyl benzoate undergoes hydrolysis when treated with water and a strong base like sodium hydroxide (NaOH) under heat. This leads to the formation of an alcohol and a carboxylic acid salt.

Principal Product#a)benzoic acid salt and ethanol (b) Ethyl benzoate + \(\mathrm{H}_{2} \mathrm{O}, \mathrm{H}_{2} \mathrm{SO}_{4}\), heat

Step 1: Acid-catalyzed hydrolysis

Ethyl benzoate undergoes acid-catalyzed hydrolysis when treated with water and sulfuric acid (H2SO4) under heat. This leads to the formation of an alcohol and a carboxylic acid.

Principal Product#b)benzoic acid and ethanol (c) Ethyl benzoate + \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}\)

Aminolysis

Ethyl benzoate reacts with the amine \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{NH}_{2}\) (normal butylamine) to form an amide and an alcohol.

Principal Product#c)N-butylbenzamide and ethanol (d) Ethyl benzoate + DIBALH \(\left(-78^{\circ} \mathrm{C}\right)\), then \(\mathrm{H}_{2}\mathrm{O}\)

Step 1: Reduction of ester with DIBALH

Ethyl benzoate undergoes partial reduction using DIBALH to transform it into an aldehyde before hydrolysis.

Principal Product#d)benzaldehyde (e) Ethyl benzoate + \(\mathrm{LiAlH}_{4}\), then \(\mathrm{H}_{2} \mathrm{O}\)

Reduction of ester with LiAlH4

Ethyl benzoate undergoes full reduction using lithium aluminum hydride (LiAlH4) to form an alcohol after hydrolysis.

Principal Product#e)benzyl alcohol (f) Ethyl benzoate + \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{MgBr}\) (two equivalents), then \(\mathrm{HCl} / \mathrm{H}_{2} \mathrm{O}\)

Step 1: Grignard reaction

Ethyl benzoate reacts with two equivalents of phenyl magnesium bromide (a Grignard reagent), followed by hydrolysis with HCl/H2O to give a tertiary alcohol.

Principal Product#f)triphenylethanol