Stereochemistry of the Enzymatic Conversion of a Δ4‐3‐Oxosteroid into a 3‐Oxo‐5β‐Steroid

摘要: The synthesis of [4-3H,4-14C]7α-hydroxycholest-4-en-3-one is described. transformation this compound into cholic acid in the bile fistula rat occurred with retention tritium label. position label isolated was established by oxidation at C-3 methylated derivative followed dehydrogenation selenium dioxide yielding methyl 7α,12α-dihydroxy-3-oxo-chol-4-enoate. This retained most Since a 3-oxo-5β-steroid could be shown to involve preferential loss 4α-hydrogen, it concluded that from located 4β-position. enzymatic reduction Δ4 double bond 7α-hydroxycholest-4-en-3-one its conversion thus involves trans diaxial addition hydrogens.