1: di(1-methyl-ethylene)zinc With diethylzinc in toluene T=20°C; 0.166667 h; 2: With (–)-MIB in toluene T=20°C; 0.166667 h; 3: benzaldehyde in toluene T=-20°C; 16 h; optical yield given as percent eeenantioselective reaction;

in tetrahydrofuran Ar-atmosphere; addn. of 0.5 equiv. ZnCl2 to organomagnesium derivative (prepd. from alkene bromide);

in tetrahydrofuran 0.5 h; Ambient temperature;