KO<sup>t</sup>Bu-mediated annulation of acetonitrile with aldehyde: synthesis of substituted dihydropyridin-2(1<i>H</i>)-ones, pyridin-2(<i>1H</i>)-ones, and thiopyridin-2(1<i>H</i>)-ones
KOtBu-mediated annulation of acetonitrile with aldehyde was observed in which cleavage of four C(sp3)–H bonds occurred, and total eight new bonds formed.