Synthesis of monosulfates of unconjugated and conjugated bile acids.

The 3-, 7- and 12-monosulfates of unconjugated, and glycine- and taurine-conjugated bile acids have been prepared. Bile acid derivatives protected by appropriate groups were sulfated in the usual manner with chlorosulfonic acid in pyridine. Subsequent removal of the protecting groups provided the desired sulfates of bile acids in satisfactory yields. The nuclear magnetic resonance spectral properties of sulfated bile acids and related compounds are briefly discussed.