Oxidative cyclization of 1,4-dienes to yield 2,3,5-trisubstituted tetrahydrofuran-diols

KMnO4 and OsO4 catalyze the oxidative cyclization of 1,4-dienes to provide 2,3,5-trisubstituted tetrahydrofuran-diols in 30% yield. This reaction proceeds stereoselectively via a proposed [3+2] cycloaddition. Competing oxidative pathways are the major non-productive processes that reduce the yield of the reaction; however, four stereogenic centers are established in one-step.