Abstract The reaction of hexamethyldiatannane (Me 3 SnSnMe 3) with metallic lithium in tetrahydrofuran (THF) has been studied by 1 H and 119 Sn NMR spectroscopy. All spectra displayed a single peak which moved gradually from the chemical shift Of Me 3 SnSnMe 3 (0.22 ppm in 1 H NMR and− 108.7 ppm in 119 Sn NMR) into those of trimethylstannyllithium (Me 3 SnLi,− 0.37 ppm,− 182.7 ppm) in 2 h. A mixture of Me 3 SnSnMe 3 and Me 3 SnLi in ...