Aerobic oxidation of alkyl- and phenyl-substituted 4-pentenols (bishomoallyl alcohols), catalyzed by cobalt(II) complexes in solutions of gamma-terpinene or cyclohexa-1,4-diene, stereo-selectively gave tetrahydrofurylmethyl radicals. Cyclized radicals were trapped with monosubstituted olefins (e.g., acrylonitrile, methyl acrylate), (E)-and (Z)-1,2-diacceptor-substituted olefins (e.g., dimethyl fumarate, fumarodinitrile, N-phenyl maleic imide), and ester-substituted alkynes (e.g., ethyl propynoate). Oxidation - addition cascades thus furnished side-chain-substituted (CN, CO2R, CUR, or SO2R) di- and trisubstituted tetrahydrofurans in stereoselective reactions (2,3-trans, 2,4-cis, and 2,5-trans). A diastereomerically pure bistetrahydrofuran was prepared in a cascade consisting of two aerobic oxidations, one alkyne addition, and one final H-atom transfer.