Chemical and physical evidence for metal–metal interchange between lithium alkoxides and di-n-butylmagnesium

Mixtures of BuLi with Mg(OCH2CH2OEt)2 and of LiOCH2CH2OEt with Bu2Mg have been studied by 1H, 13C and 7Li NMR spectra and by (6Li, 1H) HOESY experiments. It is concluded that the two systems are equivalent and give the same product. The HOESY experiments indicate that partial metal–metal interchange takes place in these two systems leading to the organometallic derivative of the more electropositive metal.