1: diazoacetic acid ethyl ester; 3-methoxy-benzaldehyde With copper(l) iodide; triphenylphosphine in dichloromethane T=40°C; Inert atmosphere; 2: diazomethane With tris(dibenzylideneacetone)dipalladium (0) in dichloromethane T=-78°C; Inert atmosphere; diastereoselective reaction;

sodium hydride in dimethyl sulfoxide 1.) room temp., 2.) room temp., 72 h;

palladium diacetate Cycloaddition;