in Petroleum ether T=-40°C; Yield given;

n-butyllithium 1.) petroleum ether, ether, -40 deg C, 15 min, 2.) -40 deg C, 30 min; Yield given. Multistep reaction;

1.) dimethoxyethane, -40 deg C, 30 min, 2.) dimethoxyethane, 2 h, 20 deg C; 5-10 mol percent excess of the lithium salt; in presence of benzo-12-crown-4, and in further solvent also; MechanismProduct distribution;