Cascade Radical 1,6-Addition/Cyclization of para-Quinone Methides: Leading to Spiro[4.5]deca-6,9-dien-8-ones.

A cascade three-component iodoazidation of para-quinone methides to construct spiro[4.5]deca-6,9-dien-8-ones under mild conditions has been developed. The chemoselective 1,6-addition of azide radical triggered a regioselective 5-exo-dig cyclization/radical coupling sequence, enabling C-N, C-C, and C-I bond formations in a one-pot procedure with high efficiency.