3-(1-Hydroxycyclohexyl)-2-propynenitrile reacts with tris[2-(4-pyridyl)ethyl]phosphine oxide to form mono-, bis- and tris{5-spirocyclohexyl-4-cyanomethylene-1,3-oxazolidine[3,2-a]-2-[4-(1,2-dihydropyridyl)]ethyl}phosphine oxides.
alkynes - pyridines - heterocycles - phosphorus - stereoselective synthesis