MHTCET 17 Apr 2026 Shift 2 Paper

Concept:DIBAL-H selectively reduces an ester to an aldehyde.Explanation:DIBAL-H (diisobutylaluminium hydride) is a mild reducing agent.It partially reduces the ester group without converting it further to an alcohol.The reaction is carried out at low temperature and then hydrolysed.The general equation is:$$\mathrm{RCOOR'} \xrightarrow{1.\ \mathrm{DIBAL-H},\ 2.\ \mathrm{H}_3\mathrm{O}^+} \mathrm{RCHO} + \mathrm{R'OH}$$Here, the ester $-\mathrm{COOR'}$ group is changed into an aldehyde $-\mathrm{CHO}$ group.Answer:The main product is $\mathrm{RCHO}$, which is option C.