The reactivity of epoxides with lithium 2,2,6,6-tetramethylpiperidide in combination with organolithiums or grignard reagents.
The 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.
Hodgson
David M
DM
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom. david.hodgson@chem.ox.ac.uk
Fleming
Matthew J
MJ
Stanway
Steven J
SJ
D000085:Acetates / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry; D000577:Amides / Q000737:chemistry; D003903:Deuterium / Q000737:chemistry; D007851:Dodecanol / Q000031:analogs & derivatives; D004852:Epoxy Compounds / Q000737:chemistry*; D018020:Lithium Compounds / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds; D011725:Pyridines / Q000737:chemistry*; D012724:Sex Attractants; D012821:Silanes / Q000737:chemistry; D013237:Stereoisomerism
C419347:3,5-dodecadienyl acetate; D000085:Acetates; D000475:Alkenes; D000577:Amides; D004852:Epoxy Compounds; D018020:Lithium Compounds; D009942:Organometallic Compounds; D011725:Pyridines; D012724:Sex Attractants; D012821:Silanes; C511847:allylsilane; C522527:lithium 2,2,6,6-tetramethylpiperidide; D007851:Dodecanol; D003903:Deuterium