23985-25-3Relevant academic research and scientific papers
Stereoselective Synthesis of (E)-α-Hydroxy-1,3-dienes via the Reaction of 2,5-Dihydrothiophene S,S-Dioxides with Carbonyl Compounds
Yamada, Sachiko,Suzuki, Hiromasa,Naito, Hiroyuki,Nomoto, Takashi,Takayama, Hiroaki
, p. 332 - 333 (1987)
A stereoselective synthesis of (E)-α0hydroxy -1,3-dienes, by thermal extrusion from adducts of 2,5-dihydrothiophene S,S-dioxide(1) with aldehydes and ketones, is presented and its extension to the synthesis of the dienone, (E)-tagetone, and of a 1,3,5-triene system, is illustrated.
Stereoselective Synthesis of (E)-Tagetone
Kunz, Joachim,Breitmaier, Eberhard
, p. 707 - 708 (2007/10/02)
(E)-Tagetone (8) was prepared in four steps by successive alkylation of 1,3-dithiane (1) by 1-iodo-2-methylpropane (2) and by 3-ethoxy-2-methylacrolein (3), followed by treatment of the intermediate 4 with sulfuric acid.Wittig alkylenation of the resulting aldehyde 5 and removal of the protecting group affords the title compound in good yield. - Key Words: Tagetes glandulifera / (E)-Tagetone / 1,3-Dithiane / Oxopropylenation / Wittig alkylenation
ACYLATION OF 1,3-ALKADIENES BY ACYL FLUOROSULFONATES. STEREOSPECIFIC SYNTHESIS OF E AND Z ISOMERS OF CONJUGATED DIENONES
Gavrishova, T.I.,Shastin, A.V.,Balenkova, E.S.
, p. 580 - 583 (2007/10/02)
Acyl fluorosulfonates generated from acyl fluorides and SO3 permits acylation of butadiene and isoprene to give triconjugated dienones.This reaction proceeds stereospecifically and leads to E isomers of the corresponding dienones in the case of butadiene and Z isomers in the case of isoprene.
Reactions with α,β-Unsaturated Nitrile Oxides. Synthetic Studies in the Terpene Field. Synthesis of Tagetones, Ocimenones, Deodarone and Atlantone
Isager, Per,Thomsen, Ib,Torssell, Kurt B. G.
, p. 806 - 813 (2007/10/02)
The generation and 1,3-dipolar cycloaddition of α,β-unsaturated nitrile oxides are described.Selective reductive cleavage of the isoxazoline ring was achived.Subsequent elimination of water leads to the 1,4-dien-3-one system.The formation of tetrahydro-γ-pyrones is observed.The reactions were applied to the synthesis of tagetones, ocimenones, deodarone and atlantone.
Trityl Salt Catalyzed Aldol Reaction between α,β-Acetylenic Ketones and Silyl Enol Ethers
Kobayashi, Shu,Matsui, Shigekazu,Mukaiyama, Teruaki
, p. 1491 - 1494 (2007/10/02)
In the presence of a catalytic amount of trityl salt, α,β-acetylenic ketones react with silyl enol ethers to afford the corresponding aldol adducts (1,2-addition products) stereoselectively in high yields.Naturally occurring monoterpenes, trans- and cis-tagetones, are synthesized by the use of this reaction.
REACTIONS OF UNSATURATED COMPOUNDS. CXIII. THE STEREOCHEMISTRY AND REGIOCHEMISTRY OF THE ACYLATION OF CONJUGATED SYSTEMS
Melikyan, G. G.,Babayan, E. V.,Atanesyan, K. A.,Badanyan, Sh. O.
, p. 1884 - 1889 (2007/10/02)
The stereochemistry and regiochemistry of the low-temperature acylation of vinylacetylene, chloroprene, bromoprene, and isoprene with carboxylic acid chlorides in the presence of aluminum chloride were studied.It was shown that mixtures of the geometric isomers of 3-chloro-1,3-alkadien-5-ones are formed in the case of vinylacetylene, and 1,4-adducts (which undergo stereoselective 1,4-dihydrochlorination with the preferential formation of cis-3-X-1,3-alkadien-5-ones) are formed in the other cases. cis-Tagetone was synthesized with a stereoisomeric purity of 83percent.
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.
NEW METHOD FOR REGIOSELECTIVE SYNTHESIS OF α-SUBSTITUTED ALLYLSILANES AND ITS APPLICATION TO THE SYNTHESIS OF E- AND Z-TAGETONES
Ochiai, Masahito,Sumi, Kenzo,Fujita, Eiichi,Tada, Shin-ichi
, p. 3346 - 3349 (2007/10/02)
Sequential addition of lithium salt of carbanion and tributylstannylmethyl iodide (3) to vinyl sulfone 2 afforded β-tributylstannyl sulfones 5, which gave substituted allylsilanes 1 in a regioselective manner by the smooth destannylsulfonation.Allylsilane 8 prepared by Michael type addition of isopropenyllithium to 2 was converted into tagetones (10). Keywords --- allylsilane; β-trimethylsylilvinyl sulfone; destannylsulfonation; tributylstannylmethyl iodide; tagetone; Michael addition
