sodium in diethyl ether; ethanol under N2, EtOH soln. of Me3SnCl and ether soln. of ligand were mixed in the dark; NH4NO3 was added, soln. was evapd., aq. phase was extd. with CH2Cl2, organic layer was dried with MgSO4, solvent was evapd., residue was chromd.; NMR;