Reaction of anabasine with 3-(1-hydroxycyclohexyl)-2-propynenitrile: a new route to functionalised anabasine alkaloids

Chemo- and regioselective addition of anabasine to 3-(1-hydroxycyclohexyl)-2-propynenitrile in ethanol results in 52% yield of a monoadduct, (Z)-3-(1-hydroxycyclohexyl)-3-[2-(3-pyridinyl)piperidino]-2-propenenitrile: in this case, only the piperidine ring of anabasine takes part in the reaction. In acetonitrile, both piperidine and pyridine rings participate in the process giving a diadduct, (Z)-3-{2-[3-[(Z)-cyanomethylidene]-2-spirocyclohexyl-8aH-[1,3]oxazolo[3,2-a]pyridine-8(2H)-yl]piperidino}-3-(1-hydroxycyclohexyl)-2-propenenitrile in 68% yield.