Organometallics – Addition to a carbonyl group (Organolithium reagent)

^{Click the structures and reaction arrows in sequence to view the 3D models and animations respectively}

Methyllithium is shown below reacting with an aldehyde. Firstly, the MeLi reacts with the ethanal to form the alkoxide.
The metal atom will coordinate with the negatively charged oxygen atom. Water is then added to protonate the
oxygen.