Stereoselective Access to Trisubstituted Cyclopentanols from Chiral Unsaturated Oxo Esters by Ketyl Radical Cyclization

Abstract Substituted cyclopentanols with three contiguous stereocenters were prepared with impressive diastereocontrol through a samarium diiodide induced 5‐ exo ‐trig radical process. The chiral unsaturated oxo ester precursors were prepared with ee values up to 90 % from propionaldehyde through a two‐step organocatalyzed aldolization and Wittig–Horner olefination reaction sequence.