title: Synthesis of 3 alpha, 7 alpha, 12 alpha-trihydroxy- and 3 alpha, 7 alpha-dihydroxy-5 beta-cholestan-26-oic acids by the use of beta-ketosulfoxide.
abstract: The biosynthetic intermediates of bile acid, 3 alpha, 7 alpha, 12 alpha-trihydroxy- and 3 alpha, 7 alpha-dihydroxy-5 beta-cholestan-26-oic acids, were synthesized by means of the thermal elimination of beta-ketosulfoxides. The alpha, beta-unsaturated ketones as key compounds of the synthesis, 3 alpha, 7 alpha, 12 alpha-trihydroxy- and 3 alpha, 7 alpha-dihydroxy-5 beta-cholest-25-en-24-ones, were effectively derived from the beta-ketosulfoxides prepared from methyl cholate or chenodeoxycholate by reaction with methylsulfinylcarbanion. These unsaturated ketones were converted into 3 alpha, 7 alpha, 12 alpha, 26-tetrahydroxy- and 3 alpha, 7 alpha, 26-trihydroxy-5 beta-cholestanes by reductive deoxygenation and hydroboration, of which stereoisomers were chromatographically separated into 25S- and 25R- isomers. The oxidation of each of the above isomeric alcohols after the protection of the hydroxyl groups on the steroidal ring and the following hydrolysis gave the title 26-carboxylic acids.
mesh_terms: D002635:Chenodeoxycholic Acid / Q000737:chemistry; D020355:Cholates; D002777:Cholestanols / Q000138:chemical synthesis*; D002793:Cholic Acids / Q000737:chemistry; D007202:Indicators and Reagents; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013454:Sulfoxides / Q000737:chemistry*
chemical_list: C000986:3,7-dihydroxycholestan-26-oic acid; D020355:Cholates; D002777:Cholestanols; D002793:Cholic Acids; D007202:Indicators and Reagents; D007659:Ketones; D013454:Sulfoxides; D002635:Chenodeoxycholic Acid; C022069:3,7,12-trihydroxycholestan-26-oic acid; C037034:methyl cholate