Asymmetric autocatalysis: triggered by chiral isotopomer arising from oxygen isotope substitution.

Trigger happy: chiral oxygen isotopomers of hydrobenzoin ([(18)O](R)-1 and [(18)O](S)-1) acted as chiral triggers to induce the enantioselective addition of iPr(2)Zn to pyrimidine-5-carbaldehyde. An extremely small chiral influence arising from the presence of the oxygen isotope ((18)O) is amplified through asymmetric autocatalysis to enantioenrich the 5-pyrimidyl alkanol product.