5597-61-5Relevant academic research and scientific papers
Intramolecular Diels-Alder reactions of 1-phenylsulfonylalka-1,2,(ω - 3),(ω - 1)-tetraenes
Bull, James R.,Gordon, Richard,Hunter, Roger
, p. 3129 - 3139 (2000)
Methods are described for conversion of a series of (E)-alka-(ω - 3),(ω - 1)-dienals 2, via ethynylation to the corresponding alkadienynols 3, followed by sequential [2,3] sigmatropic rearrangement of their derived phenylsulfenate esters and chemoselective oxidation, into 1-phenylsulfonylalka-1,2,(ω - 3),(ω - 1)-tetraenes 5, which are used to study the influence of tether length and peripheral substitution upon intramolecular cycloaddition reactivity and selectivity. It is demonstrated that (6E)-1-phenylsulfonylnona-1,2,6,8-tetraene 5c and substrates featuring an analogous ethylene linkage between the functional termini, display exceptionally high intramolecular Diels-Alder (IMDA) reactivity, accompanied by exo-diastereoselectivity. Comparative studies are described, which delineate structure-reactivity trends and demonstrate the unique capacity of the dienophilic allenyl terminus to impose reactivity-enhancing conformational constraints upon IMDA processes in favourable cases. Preliminary investigations into substrates incorporating cyclic dienyl substructures are reported, and a novel approach to spiro[4.5]decanoid ring systems is described. The Royal Society of Chemistry 2000.
EVIDENCE FOR A REVERSIBLE d,?*-COMPLEXATION, β-CUPRATION SEQUENCE IN THE CONJUGATE ADDITION REACTION OF GILMAN REAGENTS WITH α,β-ENONES.
Corey, E. J.,Boaz, Neil W.
, p. 6015 - 6018 (2007/10/02)
In situ trapping of reaction intermediates combined with stereochemical studies of the reaction of lithium dimethylcuprate with enones provides evidence for a pathway involving d,?*-cuprate-enone and copper(III) β-adducts as important intermediates in cuprate-mediated conjugate addition of carbon.
