1: (5R)-2,6-dimethyl-5-(1-methylethenyl)-2-cyclohexen-1-one With lithium diisopropyl amide in tetrahydrofuran; hexane T=-10°C; 2 h; 2: methyl iodide in tetrahydrofuran; hexane T=20°C;

N,N,N',N',N'',N''-hexamethylphosphoric triamide; sodium hydride in tetrahydrofuran T=20°C; 10 h; optical yield given as percent de;