Iterative Synthesis of Polydeoxypropionates Based on Iridium-Catalyzed Asymmetric Hydrogenation of α-Substituted Acrylic Acids.

A novel iterative protocol for the synthesis of polydeoxypropionates was developed based on iridium-catalyzed asymmetric hydrogenation of α-substituted acrylic acids. The catalyst loading can be as low as 0.01 mol %, and the overall yield for one iterative cycle is >76%. The reaction conditions are mild, and no organometallic reagents or chromatography steps are required. Using this protocol, (+)-phthioceranic acid and the polydeoxypropionate motifs of ionomycin and borrelidin were synthesized in high yield.