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 th e total synthesis of the CP molecules to accomplish the one-carbon homologa tion of sterically hindered aldehydes in the presence of acid- and base-lab ile moieties, Michael accepters, and even other carbonyl groups such as rea ctive and epimerizable ketones, Mechanistic studies have revealed a neutral reagent for the rapid collapse of cyanohydrins to ketones.