I want to do the reductive deoxygenation of an alpha-alkoxy carbonyl compound using samarium diiodide. the samarium diiodide soloution in THF is dark blue. when I add DMPU the colour does not change but when I add a soloution of alpha-alkoxy carbonyl compound in methanol a green percipitate forms after less than one minute. does it mean that somehow air is inside the reaction mixture and the samarium diiodide is reacted with air?