79994-37-9Relevant academic research and scientific papers
Synthesis of substituted hexa-3,5-dienoic acid methyl esters from conjugated dienones
Nongkhlaw,Nongrum,Myrboh
, p. 1300 - 1303 (2007/10/03)
Substituted hexa-3,5-dienoic acid methyl esters (2) were conveniently prepared in one step by 1,2-carbonyl transposition of the corresponding dienones (1) using lead(IV) acetate and boron trifluoride-diethyl ether in benzene at room temperature.
Pivotal role of (E)-3-carbamoyl-1-propenylboronic acid in the combination of Suzuki-Miyaura coupling and enzyme reactions: Synthesis of (3E,5E)-and (3E,5Z)-6-phenyl-3,5-hexadienoic acid
Sugai, Takeshi,Yokoyama, Masahiro,Yamazaki, Takahiro,Ohta, Hiromichi
, p. 797 - 798 (2007/10/03)
The first example of the enzyme-catalyzed hydrolysis of a nitrile bearing alkenylboronic acid functionality and its application to the synthesis of dienecarboxylic acids are described. (E)-3-Carbamoyl-1-propenylboronic acid was obtained by an incubation o
Rearrangement studies on 3,3-bis(methylthio)-1-(arylcyclopropyl) -2-propen-1-ols: Synthesis of functionalized cyclopentenes and polyene esters
Patro, Balaram,Deb, Bishwajit,Ila, Hiriyakkanavar,Junjappa, Hiriyakkanavar
, p. 255 - 264 (2007/10/02)
The cyclopropyl carbinols 8 and 9 obtained by either borohydride reduction (or Grignard addition) of the cyclopropyl ketones 1 are shown to undergo acid induced ring opening and intramolecular cyclization (5-exo or 6-endo) or deprotonation to afford eithe
Lithium 3-Lithio-3-tosylalkanoates: β-Acylvinyl Anion Equivalents of β-Lithiated α,β-Unsaturated Carboxylic Acids
Bonete, Pedro,Najera, Carmen
, p. 3202 - 3209 (2007/10/02)
The dilithiation of β-tosylated propanoic, 2-methylpropanoic, and butanoic acid 10 with n-butyllithium at -78 deg C leads to the corresponding lithium 3-lithio-3-tosylalkanoates 11.They react with different electrophilic reagents (deuterium oxide, iodine, trimethylchlorosilane, alkyl halides, and acyl chlorides) to give the corresponding 3-substituted tosylated alkanoic acids 12.When carbonyl compounds are allowed to react with intermediates 11 followed by in situ lactonization with trifluoroacetic anhydride and base-promoted elimination α,β-butenolides are obtained.This methodology is applied to the direct synthesis of the rosefuran lactone precursor 14cg, the O-benzyl derivative of (+/-)-umbelactone (14ch), and (+/-)-andirolactone (14ci).The alkylation and acylation reactions of organolithium compounds 11 followed by esterification with hydrogen chloride in methanol and treatment with 1,8-diazabicycloundec-7-ene (DBU) afford α,β- and/or β,γ-unsaturated esters 17 and/or 18 and unsaturated 4-keto esters 19, respectively.The last methodology has been applied to the synthesis of the unsaturated 4-keto ester 19ae precursor of the seco acid of (+/-)-pyrenophorin (22).
Novel Synthesis of Phenol Derivatives by Palladium-Catalyzed Cyclocarbonylation of 2,4-Pentadienyl Acetates
Ishii, Youichi,Gao, Chao,Xu, Wen-Xiang,Iwasaki, Masakazu,Hidai, Masanobu
, p. 6818 - 6825 (2007/10/02)
Phenyl acetates were selectively obtained in good yields by cyclocarbonylation of 2,4-pentadienyl acetates in the presence of NEt3, Ac2O, and a catalytic amount of palladium complexes such as PdCl2(PPh3)2 at 120-140 deg C under 50 atm of CO.No five-membered ring products were observed.A platinum complex PtCl2(PPh3)2 was also effective as a catalyst.The reaction of 5-phenyl-2,4-pentadienyl bromide with M(CO)(PPh3)3 (M = Pd or Pt) under CO gave the corresponding 6-phenyl-3,5-hexadienoyl complexes in a high yield, which in turn afforded 2-acetoxybiphenyl in 41-51percent yield on heating to 160 deg C under 50 atm of CO in the presence of NEt3 and Ac2O.Similar 3,5-hexadienoyl complexes are proposed to be intermediates in the catalytic cyclocarbonylation of 2,4-pentadienyl acetates.On the other hand, PdCl2(PPh3)2-catalyzed carbonylation of o-(bromomethyl)(1-alkenyl)benzenes in the presence of NEt3 and Ac2O gave 2-naphthyl acetates in moderate yields, while the reaction in the absence of Ac2O gave five-membered ring products such as 2-indanones or a tricyclic lactone by incorporation of one or two CO, respectively.
