Intramolecular propargylic reduction in γ-benzyl protected Co2(CO)6-α,γ-acetylenic diols under Nicholas reaction conditions

Lewis acid treatment of γ-benzyl protected Co2(CO)6-α,γ-acetylenic diols yielded after cobalt demetallation bishomopropargylic alcohols in good yields. The method works with both primary and secondary benzyl ethers and is compatible with many kinds of protecting groups and functionalities.