jo070291v_si_001.pdf (4.68 MB)
The Reactivity of Epoxides with Lithium 2,2,6,6-Tetramethylpiperidide in Combination with Organolithiums or Grignard Reagents
journal contribution
posted on 2007-06-22, 00:00 authored by David M. Hodgson, Matthew J. Fleming, Steven J. StanwayThe scope and limitations of lithium 2,2,6,6-tetramethylpiperidide (LTMP)-modified reductive alkylation
of epoxides is detailed. A variety of organolithiums are added to terminal and 2,2-disubstituted epoxides
in the presence of LTMP to generate alkenes in a completely regio- and highly stereoselective manner.
Arylated alkenes, dienes, allylsilanes, and enynes are accessed using this procedure. The methodology is
applied in the synthesis of the roller leaf moth pheromone, (3E,5Z)-dodecadienyl acetate. The corresponding
reaction without LTMP has also been examined, and a study using deuterated epoxides provides insight
into the mechanism. In the presence of LTMP, Grignard reagents are also shown to produce E-alkenes
directly from epoxides.