Asymmetric route to pyridines bearing a highly functionalized 2-alkyl substituent by aziridine ring-opening reactions.

The aziridine prepared from the 2-pyridineimine derived from (S)-valinol underwent ring-opening by attack of nitrogen, sulfur, and oxygen nucleophiles. Complete or prevalent regioselectivity was obtained using cerium trichloride heptahydrate as a catalyst. In some cases, the N-substituent could be removed by an oxidative protocol.