1: 3-(tetrahydro-2H-pyran-4-yl)propanoic acid With thionyl chloride 1 h; Heating / reflux; 2: 1,1-dimethylethylmagnesium chloride With copper(l) chloride in tetrahydrofuran T=0 - 20°C; 3: With water; ammonium chloride in tetrahydrofuran T=0°C;