Enantioselective Biomimetic Total Syntheses of Katsumadain and Katsumadain C

Enantioselective total syntheses of katsumadain and katsumadain C were achieved concisely through a biomimetic approach. Assembly of styryl-2-pyranone (3) and monoterpene 6 via acid-promoted regio- and stereoselective C–C bond formation afforded katsumadain (2), which underwent the photoinduced [2 + 2] dimerization in a head-to-tail mode to furnish katsumadain C (1).