n-butyllithium in tetrahydrofuran T=-78°C; 0.0333333 h;

cyclohexanone in tetrahydrofuran under argon; treatment of tin-compound in THF at -78 °C with LiBu; stirring 2 min; quenching with cyclohexanone;; poured into NH4Cl-soln. and petroleum ether; shaked 1 min; org. layer separated, washed (brine), dried (Na2SO4), filtered, concd. (vacuo); chromd. (silica gel; ethyl acetate/ petroleum ether 10:90); identical with substance produced otherwise;;