1: pentan-3-one; 2-(4-chlorobutyl)-2-ethoxy-1,3-dioxolane With 4,4'-di-tert-butylbiphenyl; lithium in tetrahydrofuran T=-78°C; Barbier-type reaction; 0.5 h; 2: With phosphate buffer T=-78 - 20°C; pH=7; 0.25 h; 3: methanol With toluene-4-sulfonic acid T=20°C;