A variety of unnatural bile acid derivatives (9a–9f) was synthesized and used to examine the specificity with which the sea lamprey (Petromyzon marinus) olfactory system detects these compounds. These compounds are analogs of petromyzonol sulfate (PS, 1), a component of the sea lamprey migratory pheromone. Both the stereochemical configuration at C5 (ie, 5α vs. 5β) and the extent and sites of oxygenation (hydroxylation or ketonization) of the bile ...
