Abstract The hexacarbonyldicobalt complexes of several appropriately designed acetylenic lactone precursors have been prepared, and lactones containing Co 2 (CO) 6-complexed triple bonds in seven-, ten-, and eleven-membered rings obtained. The latter were best obtained through a retro-Dieckmann fragmentation of 2-(hydroxybutynyl) derivatives of 1, 3- clohexanedione. Attempts to extend this reaction to cyclohexanones bearing other anion- ...
