Abstract
The carbonyl group is central in organic synthesis, thanks to its ability to undergo a vast range of different chemical transformations on its carbon center or at the neighboring positions. Due to the high level of oxygen content in biomass, small molecules arising from biomass often possess a carbonyl group. This is why biobased platform molecules possessing a carbonyl group, either under the form of an aldehyde, a ketone, an acid or an ester, play a dominant role in biobased chemistry. This review aims at illustrating how the chemistry of biobased carbonyl platform molecules with backbones from C(2) to C(6) offers opportunities to reach all kinds of chemical architectures, sometimes even complex ones benefiting from the ability of the carbonyl group to be involved in multicomponent reactions.