A novel tandem ene/Prins cyclization for the synthesis of octahydropyrano[2,3-c]pyrrole derivatives

A tandem ene/Prins cyclization of olefin tethered aldehyde with an aldehyde has been accomplished using 5 mol % scandium triflate at ambient temperature to afford a novel series of cis-fused octahydropyrano[2,3-c]pyrrole derivatives in good yields with high selectivity. This is the first report on a tandem cyclization of 4-methyl-N-(3-methylbut-2-enyl)-N-(2-oxoethyl)benzenesulfonamide with aldehydes.