1: 65 percent / iPr2NH / 1,2-dimethoxy-ethane; hexane / 2 h / Heating 2: 69 percent / tetrahydrofuran / 0.5 h / -10 °C 3: 1.05 g / KOH / ethanol; H2O / 0.75 h / 40 °C View Scheme

Multistep reaction.;

1.1: LDA / 1,2-dimethoxy-ethane / 0.33 h / -25 °C 1.2: 1,2-dimethoxy-ethane / -25 - 20 °C 1.3: 1,2-dimethoxy-ethane / 1 h / Heating 2.1: tetrahydrofuran / -25 - 20 °C 2.2: KOH; water / ethanol / 0.75 h / 40 °C 2.3: HCl; water View Scheme

Multistep reaction.;

1: α-ionone; dimethyl 2-[(2E)-3-(dimethylamino)-1-methyl-2-propenylidene]malonate With n-butyllithium; diisopropylamine in ethylene glycol dimethyl ether 1 h; Heating; 2: methylmagnesium bromide T=0°C; 3: With potassium hydroxide in ethanol; water T=40°C; 45 h; acidified with cold HCl; Further stages.;