What is the name of the product of the hydrogenation of 2-methylpropanal?

1 Answer
Dec 16, 2015

In general, the hydrogenation is supposed to reduce the compound by adding two hydrogens somewhere. The easiest place to add them is wherever the molecule is most electrophilic, so it would have to be across the carbonyl group.

The #"C"="O"# bond has the most electron density, and oxygen's higher electronegativity polarizes the bond to be partially positively charged nearer the carbon.

One actual example of hydrogenation (i.e. reduction) of an aldehyde is using #"LiAlH"_4# and then an acid workup.

We see this weird behavior from hydrogen since #"AlH"_3# is a lewis acid. due to its empty #p# orbital. It binds to the tetrahedral complex to allow favorable distribution of the carbonyl's electron density into the empty #p# orbital.