Divergent and stereoselective synthesis of dafachronic acids

A new divergent synthesis of DAF-12 ligands, namely Δ4- and Δ7-dafachronic acid, is described starting from the natural bile acid hyodeoxycholic acid. Homologation of the side chain followed by stereoselective reduction of the Δ24 olefinic linkage, 6α-dehydroxylation and C3-oxidation affords dafachronic acids in good yields and high diastereoselectivity making this approach easily accessible and scalable.