Oxidative cycloaddition of a 2-cyclohexenone or α-tetralone and an alkene with dried Mn (OAc) 3 in benzene at 80-140° C provides a general route to dihydrobenzofurans 15 and dihydronaphthofurans 17. Although the yields are modest, this one-pot reaction provides simple access to these compounds, which have previously been prepared by multistep routes. Oxidative cycloaddition of 2-cyclohexenones with β-methylstyrenes provides a ...
