acetic acid in dichloromethane byproducts: MeOH; dropwise addn. of acetic acid to a rapidly stirred soln. of Sn-complex in CH2Cl2; MeOH and solvent removal (vac.), crystn. (hexane, -45°C);

in hexane recrystn.; elem. anal.;

in chloroform PhCH(OH)CH2OH dissolved in CHCl3, Bu4(MeO)2Sn2O added, refluxed for 2 h; solvent removing;