1: tert-butyl 4-(diethoxyphosphoryl)-3-oxobutanoate With sodium hydride in tetrahydrofuran; mineral oil T=25°C; 0.0833333 h; Inert atmosphere; 2: With n-butyllithium in tetrahydrofuran; hexane; mineral oil T=-30°C; 0.0833333 h; Inert atmosphere; 3: acetaldehyde in tetrahydrofuran; hexane; mineral oil T=-30 - 20°C; Horner-Wadsworth-Emmons reaction; Inert atmosphere; diastereoselective reaction;

manganese(IV) oxide in ethyl acetate T=25°C; 5 h;

1: 1) Zn, iodine / 1) THF, reflux, 1 h, 2) Et2O, 0 deg C, 30 min 2: 73 percent / MnO2 / ethyl acetate / 5 h / 25 °C View Scheme