Beilstein J. Org. Chem.2013,9, 537–543, doi:10.3762/bjoc.9.59
[3.3.0.03,7]octane) framework by an intramolecular carbolithiationcascade involving three coupled 5-exo-trig cyclizations of the vinyllithium derived from 2-bromo-4-vinyl-1,6-heptadiene by lithium–bromine exchange was investigated. The cascade does not afford the stellane; rather, the cascade is terminated
temperature.
Keywords: carbolithiationcascade; carbometallation; intramolecular carbolithiation; intermolecular proton transfer; lithium–halogen exchange; strained hydrocarbons; Introduction
The first publication describing an intramolecular carbolithiation appeared in 1968: Drozd and co-workers reported
constructing a highly strained system by an intramolecular carbolithiationcascade involving three coupled 5-exo-trig cyclizations.
Although many strained molecules could have been selected for this exploration, the stellane framework (tricyclo[3.3.0.03,7]octane [18][19]), 1, with its mesmerizing symmetry, was