Optional ortho and lateral lithiations of 4,4-dimethyl-2-(o-tolyl)oxazolines

4,4-Dimethyl-2-(o-tolyl)oxazolines 1 undergo normal lateral lithiation at the benzylic position by treatment with sec-BuLi in diethyl ether at −78°C. In contrast, metalation of 1 with sec-BuLi/TMEDA in diethyl ether at the same temperature leads to ortho-lithiation at the 6′-position. Rationalization for the unusual ortho-lithiation of 1 is proposed.