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.