1: 2,6,6-trimethyl-cyclohexan-1-one With lithium hexamethyldisilazane in tetrahydrofuran T=0°C; 1 h; 2: chloroformic acid allyl ester in tetrahydrofuran T=-78°C;

1: 2,6,6-trimethyl-cyclohexan-1-one With lithium diisopropyl amide in tetrahydrofuran T=-78 - 0°C; 1 h; 2: Mander's reagent With N,N,N',N',N'',N''-hexamethylphosphoric triamide in tetrahydrofuran T=-78 - 20°C;

1.1: LDA / tetrahydrofuran; hexane / 1 h / 0 °C 1.2: tetrahydrofuran; hexane / 1 h / 23 °C 1.3: 69 percent / methanol; H2O; pyridine / 0.5 h / 105 °C 2.1: 82 percent / aq. HCl / diethyl ether; H2O / 3 h / 23 °C 3.1: LiHMDS / tetrahydrofuran / 1 h / 0 °C 3.2: 86 percent / tetrahydrofuran / -78 °C View Scheme