Heteroaromatic Synthesis <i>via</i> Olefin Cross-Metathesis: Entry to Polysubstituted Pyridines

The olefin cross-metathesis reaction provides a rapid and efficient method for the synthesis of α,β-unsaturated 1,5-dicarbonyl derivatives which then serve as effective precursors to mono−tetrasubstituted pyridines. Manipulation of the key 1,5-dicarbonyl intermediate allows access to pyridines with a wide range of substitution patterns. An extension of this methodology facilitates the preparation of pyridines embedded within macrocycles, as exemplified by an efficient synthesis of (R)-(+)-muscopyridine. High levels of regiocontrol, short reaction sequences, and facile substituent variation are all notable aspects of this methodology.