1: methyl 3-methyl-4-iodobenzoate With isopropylmagnesium chloride in tetrahydrofuran T=-20°C; 2 h; 2: 2,7-difluoro-3,6-bis(2-methoxyethoxymethoxy)xanthen-9-one in tetrahydrofuran T=-20 - 22°C; 16 h; 3: With trifluoroacetic acid in dichloromethane T=22°C; 2 h;