1: With (2R,3R)-(-)-di-O-(p-toluoyl)-tartaric acid in dimethyl sulfoxide T=20°C; 3 h; Resolution of racemate; 2: With sodium carbonate in dichloromethane T=20°C; 1 h; optical yield given as percent ee;

pyridine in ethyl acetate T=20°C; 1 h; optical yield given as percent ee;