New Synthetic Technology for the Mild and Selective One-Carbon Homologation of Hindered Aldehydes in the Presence of Ketones.

A selective, mild, and highly efficient method has been uncovered during the total synthesis of the CP molecules to accomplish the one-carbon homologation of sterically hindered aldehydes in the presence of acid- and base-labile moieties, Michael acceptors, and even other carbonyl groups such as reactive and epimerizable ketones. Mechanistic studies have revealed a neutral reagent for the rapid collapse of cyanohydrins to ketones.