SeO-Mediated Oxidative Transposition of Pauson-Khand Products.

Oxidative transpositions of bicyclic cyclopentenones mediated by selenium dioxide (SeO) are disclosed. Treatment of Pauson-Khand reaction (PKR) products with SeO in the presence or absence of water furnishes di- and trioxidized cyclopentenones, respectively. Mechanistic investigations reveal multiple competing oxidation pathways that depend on substrate identity and water concentration. Functionalization of the oxidized products via cross-coupling methods demonstrates their synthetic utility. These transformations allow rapid access to oxidatively transposed cyclopentenones from simple PKR products.