20432-48-8Relevant academic research and scientific papers
Studies of diastereoselectivity in Diels-Alder reactions of enantiopure (SS)-2-(p-tolylsulfinyl)-l,4-naphthoquinone and chiral racemic acyclic dienes
Carmen Carreno,Garcia-Cerrada, Susana,Urbano, Antonio,Di Vitta, Claudio
, p. 4355 - 4363 (2007/10/03)
Enantiopure sulfinylnaphthoquinone (+)-5 reacted with racemic acyclic dienes 1a-f bearing a stereogenic allylic center, through a tandem cycloaddition/pyrolytic sulfoxide elimination, to afford optically enriched compounds 8a-f and 9a-f with good like/unlike selectivities (ca. 75:25) and good enantiomeric excesses (68-82%), arising from the partial kinetic resolution of the racemic dienes. The opposite diastereoselection (8g-i: 9g- i, up to 5:95)was observed in reactions with dienes 1g-i, having an additional methyl group at C-3, the enantiomeric purities being moderate (14- 25%). Steric effects and torsional interactions in the corresponding approaches account for the observed diastereoselectivities.
CONDENSATION DES NITRILES AVEC LES ORGANOZINCIQUES ALLYLIQUES. APPLICATIONS EN SERIE TERPENIQUE
Rousseau, G.,Drouin, J.
, p. 2307 - 2310 (2007/10/02)
The reaction of 3-bromomethyl-2,5-dihydrothiophen-1,1-dioxide 6 and 2-bromomethyl-1,3-butadiene 7 with nitriles in the presence of the zinc-silver couple leads to a mixture of ketones 8,9, the pyrolysis of which give the ketones 10 and 11, corresponding respectively to acylation of isoprene at its methyl group from 8, and at C-3 from 9.The reaction of bromide 7 with nitriles leads also to the formation of ketones 10 which by acid isomerisation give the ketones 12 corresponding to an acylation at C-1 of isoprene.In the same way the reaction of 2-(1'-methyl-4'-cyclohexenyl)-3-bromo propene 13 with 3,3-dimethyl acrylonitrile give β- atlantone 14 which is isomerised in acidic medium to α-atlantone 15. 10,11-dihydro α and β-atlantone 16, 17 are obtained by the same procedure from 13 and 3-methyl butyronitrile.
