Bile acids. LII. The synthesis of 24-nor-5α-cholic acid and its 3β-isomer
摘要:
To aid in the identification of trihydroxy acidic metabolite(s) derived from beta-sitosterol, 3alpha,7alpha,12alpha-trihydroxy-24-nor-5beta-cholan-23-oic acid was prepared and its methyl ester was treated with Raney nickel in boiling p-cymene to provide methyl 3-oxo-7alpha,12alpha-dihydroxy-24-nor-5alpha-cholanate, 3-oxo-7alpha,12alpha-dihydroxy-24-nor-5beta-cholante and 3-oxo-7alpha,12alpha-dihydroxy-24-norchol-4-enoate. The latter compound was synthesized from the 3-oxo-5beta-derivative with SeO2 to provide a product with identical properties. Catalytic reduction of either saturated 3-oxo-derivative provided the appropriate 3,7,12-triols isomeric at C-3. Results from gas liquid and partition chromatography, mass spectrometry, and otherr physical properties of the acids, their methyl esters and other derivatives are compatible with the assigned structures.
Bile acids. LII. The synthesis of 24-nor-5α-cholic acid and its 3β-isomer
摘要:
To aid in the identification of trihydroxy acidic metabolite(s) derived from beta-sitosterol, 3alpha,7alpha,12alpha-trihydroxy-24-nor-5beta-cholan-23-oic acid was prepared and its methyl ester was treated with Raney nickel in boiling p-cymene to provide methyl 3-oxo-7alpha,12alpha-dihydroxy-24-nor-5alpha-cholanate, 3-oxo-7alpha,12alpha-dihydroxy-24-nor-5beta-cholante and 3-oxo-7alpha,12alpha-dihydroxy-24-norchol-4-enoate. The latter compound was synthesized from the 3-oxo-5beta-derivative with SeO2 to provide a product with identical properties. Catalytic reduction of either saturated 3-oxo-derivative provided the appropriate 3,7,12-triols isomeric at C-3. Results from gas liquid and partition chromatography, mass spectrometry, and otherr physical properties of the acids, their methyl esters and other derivatives are compatible with the assigned structures.