Abstract Oxidative coupling of 1-alkyl (benzyl)-4-(γ-pyridyl)-1, 2, 5, 6-tetrahydropyridines with acetone in the presence of KMnO 4 follows two pathways and yields both 1-R-2- (acetylmethylene) tetrahydropyridines and 1-R-3, 4-dihydroxypiperidin-2-ones. When acetonitrile is used instead of acetone, the reaction under similar conditions occurs as selective ketodihydroxylation of the starting piperideines yielding 1-R-3, 4-dihydroxy-4-(γ- ...
