A novel reaction of cyclization of 1-dodecene to cyclododecane with high selectivity, especially under moderate pressure, is found in ethanol buffered chloroaluminate ionic liquids with easy separation of product duo to the immiscibility with ionic liquids.

★★★★☆ K. Qiao, Y. Deng / Tetrahedron Letters 44 (2003) 2191–2193.