1: propargyl alcohol With n-butyllithium in tetrahydrofuran; hexane T=-78°C; Inert atmosphere; 2: isobutyraldehyde in tetrahydrofuran; hexane T=-78 - 20°C; Inert atmosphere;

toluene-4-sulfonic acid in methanol T=20°C; 2 h;

Pd-BaSO4; hydrogen in pyridine P=760.051 Torr; 1.5 h;