1: 3,5,5-trimethyl-cyclohex-2-en-1-one With n-butyllithium; diisopropylamine in tetrahydrofuran T=-78 - 0°C; 1 h; 2: [(Cyanocarbonyl)oxy]ethane With dimethyl-propylene-urea in tetrahydrofuran T=-78 - 20°C;

zinc(II) chloride in n-heptane; toluene 60 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

sodium ethanolate

boron trifluoride diethyl etherate; zinc(II) chloride 1.) heptane, toluene, reflux, 60 h, 2.) a) 0 deg C, 1 h, b) RT, 16 h; Yield given. Multistep reaction. Yields of byproduct given;

triethylsilane; boron trifluoride diethyl etherate T=80 - 95°C; 2 h;