4-(N,N-dimethlyamino)pyridine; triethylamine in dichloromethane T=0 - 20°C; Inert atmosphere;

1: 3,4-dihydro-1H-2-benzopyran With 4,4'-di-tert-butylbiphenyl; lithium in tetrahydrofuran T=20°C; 0.5 h; 2: With lithium chloride; zinc dibromide in tetrahydrofuran T=-78°C; 0.166667 h; 3: acetic anhydride in tetrahydrofuran T=-78 - 20°C; 1 h;

1: 3,4-dihydro-1H-2-benzopyran With 4,4'-di-tert-butylbiphenyl; lithium in tetrahydrofuran T=20°C; 0.5 h; 2: With zinc dibromide in tetrahydrofuran 3: acetyl chloride in tetrahydrofuran T=-78°C;

1: 3,4-dihydro-1H-2-benzopyran With 4,4'-di-tert-butylbiphenyl; lithium in tetrahydrofuran T=20°C; 0.5 h; 2: With lithium chloride; zinc dibromide in tetrahydrofuran T=-78°C; 0.166667 h; 3: acetyl chloride in tetrahydrofuran T=-78 - 20°C; 1 h;