1: trimethylsilyl 3,3-dimethylbutanoate With n-butyllithium; 1,1,1,3,3,3-hexamethyl-disilazane in tetrahydrofuran; hexane T=-78°C; 0.25 h; 2: chloro-trimethyl-silane in tetrahydrofuran; hexane T=-78 - 20°C; 12 h;

1: t-butyl acetic acid With pyridine in tetrahydrofuran T=0°C; 0.5 h; 2: chloro-trimethyl-silane With 1,1,1,3,3,3-hexamethyl-disilazane in tetrahydrofuran T=0 - 20°C; 12 h;