1: With n-butyllithium; N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran; hexane T=20°C; Metallation; 15 h; 2: With selenium; n-butyllithium; N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran; hexane T=20°C; Metallation; 12 h; 3: Hydrolysis; Acid hydrolysis;

Multistep reaction;

Yield given. Multistep reaction;

Yield given;