REGIOSELECTIVITY OF OXYSULFENYLATIONS OF CYCLOOCTA-1,5-DIENE

The regioselectivity of transannular O-hetero-cyclization of cycloocta -1,5-diene (1) with phenylsulfenyl chloride and methanol or water, res pectively, is determined by the oxy-component which acts as nucleophil ic partner in the electrophilic three component reaction. The thermody namically more stable endo, -2,6-bis(phenylsulfenyl)-9-oxabicyclo[3.3. 1]nonane (2) is formed almost exclusively in methanol while the isomer ic 9-oxabicyclo[4.2.1]nonane (3) is favored under kinetic control in t he presence of water. The oxidation of 2 or 3 yields the bissulfones 4 and 5, respectively.