An efficient and viable one-pot protocol for the synthesis of a specific class of 2-thioxothiopyrano[3,2-c] chromen-5(2H)-ones has been devised by the cross-coupling of 4-hydroxycoumarin and αenolic dithioesters under metal-and additive-free conditions in open air. The reaction proceeds via in situ generation of 4-chloro-3-formylcoumarin followed by consecutive Michael-type addition/ intramolecular cyclization/ elimination cascade, enabling the creation of thiopyran-2-thione ring over coumarin framework through successive formation of CÀ C and CÀ S bonds. Remarkably, the benign conditions, atom-economy, and quantifying forbearance of a wide horizon of functional groups are added characteristics to this strategy.