Abstract The highly nucleophilic ylide-anion of sodium-[cyano-(triphenylphosphoranylidene)- methanide] attacks oxiranes by ring-opening. Depending on the work-up-conditions and the further reactions being employed, γ-hydroxynitriles, γ-butyrolactones or α-methyleno-γ- butyrolactones are obtained from the primary products thus formed.
