in diethyl ether inert atmosphere; dropwise addn. of excess i-PrOH to Sn-compd.; solvent removal; sublimable (120°C/0.01 Torr);

in neat (no solvent) byproducts: i-PrOH, acetone; absence of air and moisture; evacuation to 0.01 Torr, heating sample to 110°C, deposition in hot zone (350°C), collecting org. products at liquid N2-temp.; cooling to 25°C over 4 h; powder X-ray diffraction, NMR spectroscopy of org. products;