Direct Stereocontrolled Synthesis of Polyoxygenated Hydrobenzofurans and Hydrobenzopyrans from p-Peroxy Quinols

An acidic-basic tandem catalytic process on p-peroxy quinols with hydroxy alkyl chains at C-4 allowed the one-pot synthesis of hydrobenzofuran and hydrobenzopyran tricyclic epoxides. In this transformation, two new cycles and four new stereogenic centers are created in a highly stereocontrolled manner. The usefulness of the strategy is illustrated with the first total synthesis and structural revision of natural product Cleroindicin D.