Brønsted Acid Mediated Annulation of α‐Hydroxy Amides with Cycloalkanones: Access to Double Spirocyclic Oxazolidin‐4‐ones

Abstract

AbstractA Brønsted acid mediated annulation of cyclic α‐hydroxy amides with cycloalkanones provide access to unusual double spirocyclic oxazolidin‐4‐one derivatives. This spirocyclization occurs in one‐pot and the overall process is highly efficient. The annulation reaction does not need metal‐catalyst. No self‐condensation of cycloalkanone occurs under acidic conditions. The synthetic technique is operationally simple and chemoselective. The transformation exhibits broad scope constructing a large array of highly functionalized complex double spirocyclic oxazolidin‐4‐one derivatives in good yields. Notably, all the reactions have been carried out in gram scale.