Route to Highly Substituted Pyridines.

Pyridine rings are common structural motifs found in a number of biologically active compounds, including some top-selling pharmaceuticals. We have developed a new approach to access substituted pyridines. The method aims to provide a reliable synthesis of a diverse range of substituted pyridines through a three-step procedure. Readily available enones are first converted into 1,5-dicarbonyls through a two-step Hosomi-Sakurai allylation/oxidative cleavage sequence, which is followed by subsequent cyclization to the corresponding pyridine using hydroxylamine hydrochloride. A variety of substituted pyridines have been synthesized using this method.