1: O,O-diethyl octylphosphonothioate With sec.-butyllithium in tetrahydrofuran; cyclohexane T=-78 - 0°C; 2: cyclohexanone in tetrahydrofuran; cyclohexane T=-78 - 20°C; Horner-Wadsworth-Emmons reaction;

1: oct-1-ene With 2,2'-azo-bisisobutyronitrile; O,O-diethyl phosphorothioite in tetrahydrofuran Heating; 2: methyl iodide With sec.-butyllithium in tetrahydrofuran; cyclohexane T=-78 - 20°C; 3: cyclohexanone With sec.-butyllithium in tetrahydrofuran; cyclohexane T=-78 - 20°C; Horner-Wadsworth-Emmons reaction; Title compound not separated from byproducts;

1.1: 99 percent / Et3B; O2 / cyclohexane / 20 °C 2.1: s-BuLi / tetrahydrofuran; cyclohexane / -78 - 0 °C 2.2: 88 percent / tetrahydrofuran; cyclohexane / -78 - 20 °C View Scheme

Schwartz's reagent 1.) CH2Cl2, 25 deg C, 1 min, 2.) CH2Cl2, 25 deg C, 12 h; Yield given. Multistep reaction;