A Catalyst‐Free Cycloaddition Reaction: Access to Spiro[chroman‐3,2’‐indene‐1’,3’‐dione] Scaffolds

We have reported herein a catalyst‐free cycloaddition of ortho ‐hydroxyphenyl‐substituted para ‐quinone methides and 2‐arylideneindane‐1,3‐diones by which a series of chromans featuring a spiro indane‐1,3‐dione scaffolds were obtained in high yields without any additives. Importantly, both anti ‐ and syn ‐ diastereomers could be obtained as single diastereomers respectively. Moverover, the current methold provides a novel and convenient approach for the efficient incorporation of the two biologically important scaffolds (chroman and spiro indane‐1,3‐dione).