1: butyl 3-oxopentanoate With bakers' yeast; phenyl vinyl thioether in ethanol; water T=20°C; Reduction; 36 h; 2: With potassium hydroxide in ethanol T=20°C; Hydrolysis; 6 h; 3: diazomethane in tetrahydrofuran; diethyl ether Methylation; Title compound not separated from byproducts;