Among the challenges facing asymmetric synthesis the selective construction of quaternary stereogenic centres, particularly those bearing all-carbon substituents, stands out. The aldol reaction has the potential to create such stereocentres, but, despite the many advances in this field, a highly selective and efficient procedure has remained elusive. Here we show that, by choosing an alternative retrosynthetic approach, such products can be prepared in a highly selective fashion. Through the consecutive addition of several organometallic derivatives, an allylzinc reagent is prepared and, on addition to an aldehyde, an aldol-type product is created. The one-pot operation involves the construction of three new carbon-carbon bonds and the formation of an all-carbon quaternary stereocentre. The products of the reaction are amenable to downstream modification, and the procedure should find applications in the fields of natural product synthesis and drug discovery.