Synthesis of new bile salt analogues, sodium 3a ,7a-di hyd roxy-5p-c holane-24-sulfonate and sodium 3a ,7p-d i hyd roxy-5p-c holane-24-su lfonate

This report describes the chemical synthesis of two new bile salt analogues, namely sodium 3a,7ar-dihydroxy-5P- cholane-24-sulfonate and sodium 3~~,7@-dihydroxy-5P-cholane- 24-sulfonate from chenodeoxycholic acid and ursodeoxycholic acid, respectively. Each common bile acid was converted into the corresponding 5@-cholane-3,7,24-triol by treatment with ethyl chloroformate in the presence of triethylamine followed by sodium borohydride reduction. Reaction of the cholanetriol with p-toluenesulfonyl chloride at 4OC afforded the partially tosylated product, 24-p-toluenesulfoxy-5@-cholane-3,7-diol, which was then treated with sodium iodide to produce 24-iodo-5B-cholane- 3,7-diol. The 24-iodide was refluxed with sodium sulfite in aque- ous ethanol to give the desired sulfonate analogue of the natur- ally occurring bile acid, chenodeoxycholic acid or ursodeoxy- cholic acid. -KKihira, K., M. Yoshii, A. Okamoto, S. Ikawa, H. Ishii, and T. Hoshita. Synthesis of new bile salt analogues, sodium 3a,7a-dihydroxy-5@-cholane-24-sulfonate and sodium 3a,7@-dihydroxy-5P-cholane-24-sulfonate. J. Lipid Res. 1990. 31: 1323-1326.