β-Substituted alkyltin halides: III. Synthesis of trialkyltin halides and tetraalkyltins

Abstract (β-Carboalkoxyethyl)tin trihalides and bis(β-carboalkoxyethyl)tin dihalides react with metallic zinc to give mixtures of the corresponding tris(β-carboalkoxyethyl)tin halides and the tetra(β-carboalkoxyethyl)tins. Bis(β-carboalkoxyethyl)tin diacetates react with metallic zinc to give only the corresponding tetra(β-carboalkoxyethyl)tin compounds. The mechanisms of these reactions are discussed. Conversion of the bis(β-carboalkoxyethyl)tin dihalides into the tris(β-carboalkoxyethyl)tin halides is believed to occur by a two-step process, with the tetra(β-carboalkoxyethyl)tin compounds as intermediate products. The 270 MHz NMR spectra of the (β-carbobutoxyethyl)tin compounds are presented.