1884-50-0Relevant articles and documents
UN NOUVEAU REACTIF DE PRENYLATION : LE LITHIO-1 METHYL-2 TRIMETHYLSILOXY-4 BUTADIENE
Duhamel, L.,Duhamel, P.,Lecouve, J.P.
, p. 4339 - 4348 (1987)
This new reagent is obtained by bromine-lithium exchange using tertiobutyllithium in ether at -70 deg C.Its condensation with carbonyl compounds followed by hydrolysis in mild conditions leads to polyenals with good yields.Synthesis of retinal from β-ionylidenacetaldehyde is described.
Oxidative γ-addition of enals to trifluoromethyl ketones: Enantioselectivity control via lewis acid/n-heterocyclic carbene cooperative catalysis
Mo, Junming,Chen, Xingkuan,Chi, Yonggui Robin
, p. 8810 - 8813 (2012/07/02)
An oxidative γ-functionalization of enals under N-heterocyclic carbene (NHC) catalysis to give unsaturated δ-lactones is disclosed. Enantioselectivity control involving the relatively remote enal γ-carbon was achieved via Lewis acid [Sc(OTf)3 or combined Sc(OTf) 3/Mg(OTf)2] and NHC cooperative catalysis.
Heck reactions of crotonaldehyde
Stadler, Michael,List, Benjamin
, p. 597 - 599 (2008/12/22)
A direct method for the synthesis of β,β-disubstituted-α, β-unsaturated aldehydes via Heck reaction of aryl halides with crotonaldehyde and related substrates has been developed. The reaction provides rapid access to products usually prepared via multistep sequences. The power of the method in combination with an organocatalytic transfer hydrogenation is illustrated with a short asymmetric synthesis of (S)-Florhydral. Georg Thieme Verlag Stuttgart.
HISTONE DEACETYLASE INHIBITORS
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Page/Page column 15-16, (2008/06/13)
Hormone refractory metastatic disease can be treated with an oxyamide-containing compound through the inhibition of HDAC1 or HDAC2.
Obtention of 2,2-(diethoxy) vinyl lithium and 2-methyl-4-ethoxy butadienyl lithium by Arene-catalysed lithiation of the corresponding chloro derivatives. Synthetic applications
Si-Fodil, Mohamed,Ferreira, Humberto,Gralak, Jean,Duhamel, Lucette
, p. 8975 - 8978 (2007/10/03)
Vinylic lithium reagents 1 and 2 could be obtained by the title procedure from their chloro precursors 5 and 6 instead of the less stable corresponding bromo derivatives 3 and 4. Condensation with carbonyl compounds leads to interesting synthetic applications such as a two steps synthesis of retinal 13 from β-cyclocitral 10.
A New Prenylation Method using the Lithium Enolate of Prenal. Reaction with Aldehydes and α,β-Unsaturated Aldehydes
Duhamel, Lucette,Guillemont, Jerome,Poirier, Jean-Marie,Chabardes, Pierre
, p. 4495 - 4498 (2007/10/02)
A γ-condensation of the enolate of prenal 1 is observed with aldehydes and α,β-unsaturated aldehydes.In this case, a conjugate addition is obtained.Intermediate dihydropyrans 4 yield dienals 5 by hydrolysis.Keywords: Lithium enolate of prenal, dihydropyrans, dienals, γ-addition, prenylation.
New Functionalized Horner-Wadsworth-Emmons Reagents: Useful Building Blocks in the Synthesis of Polyunsaturated Aldehydes. A Short Synthesis of (+/-)-(E,E)-Coriolic Acid
Kann, Nina,Rein, Tobias,Akermark, Bjoern,Helquist, Paul
, p. 5312 - 5323 (2007/10/02)
The new Horner-Wadsworth-Emmons reagents 4 and 5 transform carbonyl compounds into 2,4-pentadienals and 3-methyl-2,4-pentadienals, respectively.Reagent 4 gives good yields of the desired products with a variety of aldehydes and ketones; reagent 5 generally gives good yields with aldehydes, but gives lower yields with ketones.The reactions proceed under mild conditions and give the products as predominantly 2E,4E isomers, with moderate to good stereoselectivity.In general, pure samples of the 2E,4E-dienals can be obtained after chromatography.Reagents 4 have been used in the key step in a short synthesis of (+/-)-13-hydroxy-9(E),11(E)-octadecanoic acid ((E,E)-coriolic aicd, 45).
