sodium methoxide in methanol under N2; ligand (1 equiv.) added to soln. of NaOMe in MeOH; stirred for30 min; Ph3SnCl (1 equiv.) added; reacted at 60°C for 12 h; cool ed to room temp.; filtered; solvent removed gradually from filtrate by evapn. under vac.; recrystd. from MeOH; elem. anal.;