DIBAL-H i.e., Di isobutyl aluminium hydride causes partial reduction of cyanide group along with the ester group and further hydrolysis forms corresponding aldehyde as the product. The reaction is as follows,
CH3(CH2)5COOC2H5→ DIBAL- H,H2OCH3(CH2)5CHO
The Clemmensen reduction is a reaction that is used to reduce aldehydes or ketones to alkanes using hydrochloric acid and zinc amalgam.
{C}_{6}{H}_{5}{\mathrm{COC}}_{6}{H}_{5}\overset{\mathrm{Zn}(\mathrm{Hg})&\text{ conc. }\mathrm{HCl}}{\rightarrow }{C}_{6}{H}_{5}{\mathrm{CH}}_{2}{C}_{6}{H}_{5}
A Grignard reagent is an organomagnesium compound which can be described by the chemical formula ‘R-Mg-X’ . Here aldehyde will react with Grignard's reagent to give alcohol.
C6H5CHO→H2OCH3MgBrC6H5CH(OH)CH3
CH3COCH2COOC2H5→NaBH4,H+CH3CH(OH)CH2COOC2H5
In this reaction, NaBH4,H+ is used as a reducing agent, to get CH3CH(OH)CH2COOC2H5 as a product.
Hence option B is the answer.
