1: With triphenylphosphine in benzene T=20°C; 24 h; 2: With sodium metaborate; dihydrogen peroxide in acetic acid T=80°C; 5 h; 3: With trichlorophosphate 6 h; Heating; Title compound not separated from byproducts;

1.1: MeLi; iPr2NH / diethyl ether / -78 °C 1.2: 69 percent / diethyl ether / 0.5 h / -90 °C 2.1: 79 percent / bromine / pentane / 0.5 h / -78 °C 3.1: 100 percent / NaN3 / acetic acid; ethanol; H2O / 20 h / 0 °C 4.1: PPh3 / benzene / 24 h / 20 °C 4.2: NaBO2*H2O2*3H2O / acetic acid / 5 h / 80 °C 4.3: POCl3 / 6 h / Heating View Scheme

1.1: 100 percent / NaN3 / ethanol; H2O; acetic acid / 20 h / 0 °C 2.1: PPh3 / benzene / 24 h / 20 °C 2.2: NaBO2*H2O2*3H2O / acetic acid / 5 h / 80 °C 2.3: POCl3 / 6 h / Heating View Scheme

1.1: 79 percent / bromine / pentane / 0.5 h / -78 °C 2.1: 100 percent / NaN3 / acetic acid; ethanol; H2O / 20 h / 0 °C 3.1: PPh3 / benzene / 24 h / 20 °C 3.2: NaBO2*H2O2*3H2O / acetic acid / 5 h / 80 °C 3.3: POCl3 / 6 h / Heating View Scheme

1.1: 83 percent / bromine / pentane / 0.5 h / -78 °C 2.1: 100 percent / NaN3 / ethanol; H2O; acetic acid / 20 h / 0 °C 3.1: PPh3 / benzene / 24 h / 20 °C 3.2: NaBO2*H2O2*3H2O / acetic acid / 5 h / 80 °C 3.3: POCl3 / 6 h / Heating View Scheme

1.1: MeLi; iPr2NH / diethyl ether / -78 °C 1.2: 58 percent / diethyl ether / 0.5 h / -90 °C 2.1: 83 percent / bromine / pentane / 0.5 h / -78 °C 3.1: 100 percent / NaN3 / ethanol; H2O; acetic acid / 20 h / 0 °C 4.1: PPh3 / benzene / 24 h / 20 °C 4.2: NaBO2*H2O2*3H2O / acetic acid / 5 h / 80 °C 4.3: POCl3 / 6 h / Heating View Scheme

1.1: 100 percent / NaN3 / acetic acid; ethanol; H2O / 20 h / 0 °C 2.1: PPh3 / benzene / 24 h / 20 °C 2.2: NaBO2*H2O2*3H2O / acetic acid / 5 h / 80 °C 2.3: POCl3 / 6 h / Heating View Scheme

Multistep reaction. Title compound not separated from byproducts;