1: With silver trifluoromethanesulfonate T=-78°C; Friedel-Crafts acylation reaction; 0.666667 h; 2: With iodine in tetrachloromethane 5 h; UV-irradiation;

1: (chloromethyl)-triphenylphosphonium chloride With n-butyllithium in tetrahydrofuran; hexane T=0°C; 1 h; 2: 7-acetylbenzo[b]oxepine-3-one in tetrahydrofuran; hexane T=0°C; Wittig olefination; 0.5 h; Further stages. Title compound not separated from byproducts.;

1.1: 35 mg / DBU / CH2Cl2 / 0.08 h / 20 °C 2.1: n-BuLi / hexane; tetrahydrofuran / 1 h / 0 °C 2.2: hexane; tetrahydrofuran / 0.5 h / 0 °C View Scheme

1.1: O3 / CH2Cl2 / -78 °C 1.2: Me2S / CH2Cl2 / 14 h / 20 °C 2.1: 35 mg / DBU / CH2Cl2 / 0.08 h / 20 °C 3.1: n-BuLi / hexane; tetrahydrofuran / 1 h / 0 °C 3.2: hexane; tetrahydrofuran / 0.5 h / 0 °C View Scheme

1.1: 67 percent / NBS; Bz2O2 / CCl4 / 20 h / Heating 2.1: t-BuOK / tetrahydrofuran / 1 h / -78 °C 2.2: 76 percent / tetrahydrofuran / 0.67 h / -78 °C 3.1: AgTf / 0.67 h / -78 °C View Scheme

1.1: t-BuOK / tetrahydrofuran / 1 h / -78 °C 1.2: 76 percent / tetrahydrofuran / 0.67 h / -78 °C 2.1: AgTf / 0.67 h / -78 °C View Scheme