Synthesis of Carbonyl Compounds From Nitriles

Nitriles can be reduced to amines by either catalytic hydrogenation or lithium aluminum hydride. However, the modified hydride reagent lithium triethoxyaluminum hydride adds to the bond only once to give an imine anion derivative. 

Treating the aluminum anion with aqueous acid yields an imine that is rapidly converted to an aldehyde. We will discuss the relative stabilities of imines and carbonyl groups in the next chapter. 

Grignard reagents add to the triple bond of a nitrile to give an imine anion complexed with magnesium. The intermediate imine anion has a double bond, which might add a second equivalent of the Grignard reagent. However, this addition reaction does not occur under the reaction conditions. 

Treating the magnesium salt of the imine with aqueous acid rapidly gives the more stable ketone. 

Draw the structure of the product of each of the following reactions. 

---