Dearomatization of Halonaphthols via an Intermolecular [4＋1] Spiroannulation with in situ Formed Aza-ortho-quinone Methides

A base promoted dearomatization strategy for [4＋1] spiroannulation of halonaphthols with N-(o-chloromethyl) aryl amides is reported, which is used to efficiently synthesize azaspirocycles.A range of azaspirocycles were obtained in satisfactory to excellent yield with high diastereoselectivity under mild conditions.Variety functional groups including aldehyde and free hydroxyl group, and different N-protecting groups, such as Bz and Ts are compatibility.The transformation of the product and a possible mechanism were also provided.