1: With iodine; magnesium; ethylene dibromide in tetrahydrofuran T=20°C; 1 h; 2: 2-bromo-naphthalene in tetrahydrofuran T=5 - 40°C; 1 h; 3: phosphorous acid diethyl ester in tetrahydrofuran T=5°C; 3 h;

1: 2-bromo-naphthalene With iodine; magnesium in tetrahydrofuran Inert atmosphere; 2: phosphonic acid diethyl ester in tetrahydrofuran T=0°C; 2.25 h; Inert atmosphere;

in diethyl ether