Biomimetic Total Synthesis of (±)-Lappaceolides A and B

The first total synthesis of lappaceolides A and B is achieved in two steps by using a biomimetic vinylogous-Michael–oxa-Michael domino reaction. The domino reaction proceeds with Cs2CO3 in 1,2-DCE at elevated temperatures and requires careful kinetic control. The total synthesis provides further proof of the biosynthetic hypothesis of lappaceolides being dimers of the natural product siphonodin.