1: (5-carboxy-l-pentyl)triphenylphosphonium bromide With sodium hexamethyldisilazane in tetrahydrofuran T=20°C; 2 h; Inert atmosphere; 2: pentanal in tetrahydrofuran T=20°C; Wittig reaction; 3 h; stereoselective reaction;

ethanol; nickel Hydrogenation;

1.1: sulfuric acid; hydrogen bromide / 7 h / 20 °C / Reflux 2.1: toluene / 48 h / Inert atmosphere; Reflux 3.1: sodium hexamethyldisilazane / tetrahydrofuran / 2 h / 20 °C / Inert atmosphere 3.2: 3 h / 20 °C View Scheme

1.1: toluene / 48 h / Inert atmosphere; Reflux 2.1: sodium hexamethyldisilazane / tetrahydrofuran / 2 h / 20 °C / Inert atmosphere 2.2: 3 h / 20 °C View Scheme