Computational study of the stereochemistry of intramolecular carbolithiation of an alkene by a secondary alkyllithium: stereochemistry change caused by a single THF molecule of solvation.
Theoretical calculations reveal that the 40:1 ratio of trans- to cis-2-methylcyclopentylmethyllithium formed in the cyclization of 6-lithio-1-heptene by intramolecular carbolithiation is due to steric crowding in the transition state for the cis-cyclization pathway when a single THF molecule complexes the lithium cation. In the absence of this specific solvation, the cis-cyclization pathway is predicted to be slightly favored.
Liu
Hanbin
H
Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Deng
Kai
K
Cohen
Theodore
T
Jordan
Kenneth D
KD