Structural Analysis and Thermal Stability of 1-Lithio-2-trimethylsiloxyethylene in Diethyl Ether Solution

Abstract

¹H and ¹³C NMR spectroscopy, a structural analysis of 1-lithio-2-trimethylsiloxyethylene, formed in Et₂O solution, has shown a mixture of several solution species at –75 °C; this carbanion 1, stable for a long time at –75 °C, undergoes a degradation reaction when the temperature increases to afford by-products, all of which have been analysed and their percentages determined for each temperature.

References

1. (a) L. Duhamel and F. Tombret, J. Org. Chem., 1981, 46, 3741; (b) L. Duhamel, F. Tombret and Y. Mollier, J. Organomet. Chem., 1985, 280, 1.
2. The isobutene is formed by dehydrohalogenation of Bu^tBr by an excess of Bu^tLi. For all the ¹H spectra analysed, the percentages of the different species were determined with regard to the ethylenic signal of the isobutene (δ_H 4.60).