Regioselective Synthesis of 3‐Hydroxy‐4,5‐alkyl‐Substituted Pyridines Using 1,3‐Enynes as Alkynes Surrogates.

1,3-enynes are convenient surrogates of internal alkynes bearing two alkyl substituents in their nickel-catalyzed [4 + 2] cycloaddition with 3-azetidinones.