1.1: potassium tert-butylate / tetrahydrofuran / 8 h / |Reflux 2.1: magnesium; iodine / 2.5 h / 40 °C / |Reflux 2.2: -20 °C View Scheme

1.1: bromine / dichloromethane / 35 °C 2.1: potassium tert-butylate / tetrahydrofuran / 8 h / |Reflux 3.1: magnesium; iodine / 2.5 h / 40 °C / |Reflux 3.2: -20 °C View Scheme

1: 1-bromo-2-ethoxy-4-tert-butylbenzene With iodine; magnesium T=40°C; 2.5 h; Reflux; 2: carbon dioxide T=-20°C;