Stereodiverse Iterative Synthesis of 1,3-Polyol Arrays through Asymmetric Catalytic Hydrogenation. Formal Total Synthesis of (-)-Cyanolide A.

An iterative protocol was developed for highly diastereo- and enantioselective construction of high-order 1,3-polyols via iridium-catalyzed asymmetric hydrogenation of β-alkyl-β-keto esters. The protocol involves four operations-asymmetric hydrogenation, hydroxy protection, ester hydrolysis, and C-acylation-and the catalyst loading can be as low as 0.005 mol %.