${\mathrm{CH}}_3\mathrm{C}\equiv \mathrm{N}\to {\mathrm{CH}}_3\mathrm{CHO}$ Reagents useful for this conversion is / are

 This is Stephen's reaction, which involves the conversion of an alkyl cyanide to an aldehyde using SnCl2/HCl as a reducing agent.
b) DIBAL−H, also reduces the nitrile group to an aldehyde.
c) Pd−BaSO4 will not reduce alkyl cyanide into aldehyde.

 $\mathrm{RC}\equiv \mathrm{N} \stackrel{\stackrel{{\mathrm{SNCl}}_2/\mathrm{HCl}}{ }}{\to }$R−CHO
$\mathrm{RCN}\stackrel{\mathrm{DIBAL}-\mathrm{H},{\mathrm{H}}^{+}/{\mathrm{H}}_2\mathrm{O}}{\to }$RCHO