Highly effective transition structure designed catalyst for the enantio- and position-selective dihydroxylation of polyisoprenoids.

[structure: see text] The chiral monocinchona derivative shown, synthesized in one step from two efficiently prepared chiral building blocks, was designed under mechanistic guidance as a catalyst for the enantio- and position-selective dihydroxylation of the terminal isopropylidene group of polyisoprenoids. Its efficacy as a synthetic reagent for this purpose was demonstrated for several different substrates.