Time‐Economical Synthesis of Bis‐spiro Cyclopropanes via Cascade 1,6‐Conjugate Addition/Dearomatization Reaction of para‐Quinone Methides with 3‐Chlorooxindoles

A simple method involving DBN‐mediated spirocyclopropanation of para‐quinone methides with 3‐chlorooxindoles is reported, providing a novel class of bis‐spiro compounds in short reaction times under mild conditions. Twenty‐four examples of the target compounds were obtained in up to 96 % yield.