sodium hydroxide; Tetrahexylammonium bromide in diethyl ether; water T=0°C; 3 h;

tetrabutyl ammonium fluoride in tetrahydrofuran; diethyl ether T=0°C; Addition; 2 h;

1: ethyl acetoacetate With sodium hydroxide; 4-toluenesulfonyl azide; Tetrahexylammonium bromide in diethyl ether; water T=20°C; 1.5 h; 2: isobutyraldehyde in diethyl ether; water T=0°C; aldol reaction; 3 h; Further stages.;

CaH2; boron trifluoride diethyl etherate Ambient temperature;

hydrogen; palladium on activated charcoal in methanol P=3040 Torr; 1 h; Ambient temperature;