Cope Rearrangement

To a solution of the 1,5-dien-3-ol (84.2 mmol, 1.0 eq) in 500 mL THF was added 18-C-6 (1.2 eq). The round-bottom flask was immersed in an ice bath, and KH (1.2 eq) was added in one portion. The reaction mixture was stirred for 2 h at the same temperature. The reaction was slowly quenched with MeOH at -78 °C. The solution was concentrated in vacuo, and the obtained residue was purified by flash column chromatography on silica gel to give the unsaturated carbonyl compound  (97% yield).