triphenylphosphine; nanocrystalline aerogel prepared MgO in N,N-dimethyl-formamide T=20°C; Wittig reaction; 11 h;

1: t-butyl 2-(diethoxyphosphoryl)acetate With methylmagnesium bromide in tetrahydrofuran; diethyl ether T=20°C; Wadsworth-Emmons reaction; 0.25 h; Inert atmosphere; 2: isovaleraldehyde in tetrahydrofuran; diethyl ether Wadsworth-Emmons reaction; RefluxInert atmosphere; diastereoselective reaction;

1: t-butyl 2-(diethoxyphosphoryl)acetate With n-butyllithium in tetrahydrofuran; hexane T=-78°C; Wadsworth-Emmons reaction; 0.5 h; Inert atmosphere; 2: isovaleraldehyde in tetrahydrofuran; hexane T=-78 - 20°C; Wadsworth-Emmons reaction; Inert atmosphere; optical yield given as percent de;

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 92 percent / tetrahydrofuran; hexane / 3 h / -78 °C 2.1: 90 percent / H2; acetic acid / Pd(OH)2/C / methanol; H2O / 24 h / 20 °C / 760.05 Torr 3.1: 92 percent / trifluoroacetic acid / CH2Cl2 / 15 h / 20 °C View Scheme

1.1: n-BuLi / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: 95 percent / tetrahydrofuran; hexane / 3 h / -78 °C 2.1: 91 percent / H2; acetic acid / Pd(OH)2/C / methanol; H2O / 24 h / 20 °C / 760.05 Torr 3.1: 97 percent / trifluoroacetic acid / CH2Cl2 / 15 h / 20 °C View Scheme