Synthesis of 1β‐hydroxydeoxycholic acid in H‐2 and unlabeled forms

1β–hydroxydeoxycholic acid in unlabeled and stable isotope labeled forms was required for use as a biomarker for Cytochrome P450 3A4/5 activity. A lengthy synthesis was undertaken to deliver the unlabeled compound and in the process, to develop a route to the deuterium labeled compound. The synthesis of the unlabeled compound was completed but in a very low yield. Concurrent with the synthetic approach, a biosynthetic route was pursued and this approach proved to be much more rapid and afforded the compound in both unlabeled and deuterium labeled forms in a 1‐step oxidation from deoxycholic acid and [D 4 ]deoxycholic acid, respectively.