1: isopropyl 4-hydroxy-3-iodobenzoate With methyl-magnesium chloride in tetrahydrofuran T=-10°C; 0.25 h; 2: With isopropylmagnesium chloride in tetrahydrofuran T=-10°C; 2.5 h; 3: 2,2-dimethyl-cyclopentanone Further stages;