mild and efficient solvent-free tetrahydropyranylation (thp) of alcohols catalyzed by reusable acidic ionic liquid [et3n(ch2)4so3h][ots]

a variety of alcohols readily add to 3,4-dihydro-2h-pyran under solvent free conditions in the presence of catalytic amount of acidic ionic liquid [et3n(ch2)4so3h][ots] to afford the corresponding tetrahydropyranyl ethers in good to excellent yields at room temperature. the use of this procedure allows easy separation of the desired products from ionic liquid and recycling the ionic liquid. some of the major advantages of this procedure are nonaqueous work-up, very good yields, catalytic amount of catalyst and reusability of ionic liquid.