Cyclohexenones, solution-phase

To a solution of 6.99 g (25.3 mmol) of 2,3,4-trimethyl-4-(5-trimethylsilyl-3-pentynyl)-2-cyclohexenone in 150 mL of C HjClj are added at —78 C 5.1 mL (44 mmol) of TiCl4, and the resultant mixture is stirred for 30 min at —78 "C. The mixture is quenched at low temperature with 100 mL of water and extracted with three 50-mL portions of Ch,C12. The combined organic phase is washed with 150 ml, of brine and dried over MgS04. The solvent is removed in vacuo and the crude product is flash chromatographed (EtOAc/ petroleum ether 3 97) to give the pure product as a 2 1 mixture of diastcreomers yield 4.32 g (84%) d.r. 2 1. 

To a suspension of cuprous iodide (0.03 mol) in 100 ml THF was added 25 ml dimethyl sulfide. The solution was cooled to -78 °C, phenyl magnesium bromide (0.06 mol) dissolved in diethyl ether added, stirred one hour, and 2-cyclohexenone (0.03 mol) dissolved in 10 ml THF added. The mixture was warmed to 0°C over 2 hours then re-cooled to -78 °C. It was treated with 15 ml hexamethyl-phosphoramide, stirred 30 minutes, treated with methyl cyanoformate (0.09 mol), and warmed to ambient temperature overnight. The mixture was poured into 100 ml 2M HCl, the organic phase separated, and the aqueous phase extracted with CH2CI2. The combined organic extracts were concentrated, the residue triturated with NH4CI, water, brine, dried, and 3.2 g product isolated as an oil. 

Amides induce anionic polymerization of olefins like styrene, methyl methacrylate, acrylonitrile [5], cyclohexenone [6], and ethylene oxide [7] in solution. The amination of ethene and propene by NH3 in the gas phase or in NH3 solution is catalyzed by amides [8]. 

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