New Syntheses of Dilithiotrimethylenemethane: An Ionic Energy Minimum

Article abstract of DOI:10.1021/jo00303a022

Thermal rearrangement of monolithium organic compounds, without β-hydrogens, have been shown to produce gem-dilithio organic molecules.The synthesis of three monolithium olefins, namely, 1-lithio-2-methylpropene (1), 3-lithio-2-methylpropene (2), and 1-lithio-2,2-diphenylethylene (3), from their respective tin derivatives are described.The thermal rearrangement of these lithiated olefins did not produce the expected geminal compounds.Both 1 and 2 produced the thermodynamically stable dilithiotrimethylenemethane, while 3 produced as the major product the coupled organic moiety 1,1,4,4-tetraphenyl-1,3-butadiene.