- A structure-taste study of arylsulfonyl(cyclo)alkanecarboxylic acids
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A number of sweeteners contain a sulfonyl group. In our current search for new glucophores several new compounds containing such group were obtained. A series of novel 1-phenylsulfonylcyklohexanecarboxylic acids and 2-arylsulfonylalkanecarboxylic acids was obtained and evaluated for their sweet taste quality. It has been found that methyl substituents are of the key importance for the activity of these compounds.
- Lysiak, Violetta,Ratajczak, Aleksander,Mencel, Agnieszka,Jarzembek, Krystyna,Polanski, Jaroslaw
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p. 671 - 675
(2007/10/03)
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- Lithium 3-Lithio-3-tosylalkanoates: β-Acylvinyl Anion Equivalents of β-Lithiated α,β-Unsaturated Carboxylic Acids
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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).
- Bonete, Pedro,Najera, Carmen
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p. 3202 - 3209
(2007/10/02)
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- Lithium 3-lithio-3-tosylpropanoate: A useful α-tosylated homoenolate anion
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Lithium 3-lithio-3-tosylpropanoate prepared by dilithiation of 3-tosylpropanoic acid with n-butyllithium at -78°C, reacts with different electrophiles yielding the expected 3-functionalized tosylated propanoic acids. When carbonyl compounds are used as electrophiles the corresponding α,β-butenolides are prepared directly.
- Bonete,Najera
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p. 4065 - 4068
(2007/10/02)
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