Interaction of Alkyl Pyridines with Aldehydes aad Phthalic Anhydride

4-Ethylpyridine readily reacts with formaldehyde to form 2-(4'-pyridyl)propanol(1) and \(\gamma\)-picoline with cinnamic aldehyde affords 1-(4'-pyridyl)-2-hydroxy-4-phenyl-Δ³ -butylene (II) and 1-(4'-pyridyl)-4-phenyl­hutadiene(III). (I) and (III) are easily oxidised to isonicotinic acid. whereas 4-ethylpyridine fails to react; \(\gamma\)-picoline and 2, 6-lutidine condonse with phthalic anhydride, catalysed by fused zinc chloride or acetic anhydride to afford 4-pyrophthalone (VI), 6-methylpyrophthalone (IV), and 2, 6-bis-pyrephthalone (V).