Total synthesis of (±)-bruguierol A via an intramolecular [3+2] cycloaddition of cyclopropane 1,1-diester

Total synthesis of natural product (±)-bruguierol A was accomplished in 10-steps and with an overall 16.8% yield. The embedded unique 8-oxabicyclo3.2.1]octane core skeleton in this natural product was constructed via a novel Sc(OTf)₃-catalyzed intramolecular 3+2] cycloaddition of cyclopropane, which was developed recently in this laboratory. This general synthetic strategy can be potentially applied to the synthesis of a broad range of structurally related natural products.