Chemical conversion and mechanism of transformation of a 3,5-dienyl steroid precursor to 6β-hydroxytesosterone, the major product of the drug metabolizing enzyme, cytochrome P450 3A4

6β-Hydroxytestosterone has been studied extensively due to its role as the main product of the metabolism of testosterone by P450 3A4, the major drug metabolizing enzyme in the liver. However, a robust synthetic route to 6β-hydroxytesosterone has yet to be reported. Herein we describe the synthesis of 6β-hydroxytestosterone from dehydroepiandrosterone. This approach consists of the oxidation of a key 3,5-dienyl steroid precursor under Uemura-Doyle conditions resulting in the 3-keto Δ⁴ – steroid backbone with the C6β-hydroxy group. Regioselective incorporation of deuterium at the C3 position of the 3,5-diene intermediate allowed for elucidation of the mechanism. Retention of the deuterium atom at C4 of the product demonstrated a 1,2-hydride shift during the conversion of the 3,5-diene to the 3-keto Δ⁴-6β-hydroxy steroid moiety. This strategy can be employed to explore other physiologically relevant compounds bearing the 3-keto-Δ⁴ steroid backbone with a C6β-hydroxy group.

6β-hydroxytesotsterone was synthesized through the oxidation of a 3,5-dienyl steroid precursor