- Iodine(III)-Mediated Contraction of 3,4-Dihydropyranones: Access to Polysubstituted γ-Butyrolactones
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Functionalized γ-butyrolactones are privileged structures in the field of medicinal chemistry; they are found in numerous natural products and synthetic compounds with diverse biological activities. The oxidative ring contraction of 3,4-dihydropyran-2-one derivatives represents a promising yet underappreciated strategy to access these compounds. To the best of our knowledge, very few examples of this strategy have been reported, with limited investigation of the influence of stereogenic centers on the starting dihydropyranones. We investigated the iodine(III)-mediated contraction of a representative set of dihydropyranone derivatives. The method gives rapid access to functionalized γ-butyrolactones in good yields. The reaction scope was investigated, and the method was found to support various levels of substituents, even enabling access to sterically congested quaternary centers. The stereoselectivity was investigated using chiral substrates and a chiral iodine(III) reagent.
- Dagenais, Robin,Lussier, Tommy,Legault, Claude Y.
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p. 5290 - 5294
(2019/09/03)
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- PHOTOLABILE PRO-FRAGRANCES
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Many fragrances that provide a scent of freshness tend to be highly volatile and are therefore not very economical when used in typical applications such as washing or cleaning processes, so they have to be used in relatively large quantities to be able to produce adequate effects. The disclosed photolabile pro-fragrances provide a much longer-lasting sense of fragrance, in particular with a scent of freshness, when used in typical applications, thus allowing said fragrances to be used efficiently.
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Page/Page column 0094-0102
(2015/04/15)
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- Synthesis and reactivity of methyl 3-acyl-6-amino-4-aryl-5-cyano-4h-pyran- 2-carboxylates
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By treating arylidenemalononitriles with methyl 2,4-dioxobutanoates, derivatives of 4H-pyrans - methyl 3-acyl-6-amino-4-aryl-5-cyano-4H-pyran-2- carboxylates - are obtained, which are novel, promising structural components for the synthesis of carbo- and
- Sheverdov,Andreev, A. Yu.,Ershov,Nasakin,Tafeenko,Gein
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p. 997 - 1005
(2013/03/13)
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- Synthesis and Stereochemistry of cis- and trans- 4,6-Diaryl-2-piperidones
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Two-carbon 1,4-addition to variously substituted chalcones (3) and subsequent two-step reductive amination, and cyclisation via oxime intermediates resulsts in cis- (1) and trans- (2) 4,6-diarylpiperidones in high yields.The configuration and conformation
- Rao, H. Surya Prakash,Bharathi, B.
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p. 541 - 554
(2007/10/02)
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- Reductive Cleavage of Arylcyclopropyl Ketones
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Arylcyclopropyl aryl ketones undergo clean but slow reductive cleavage to 4-arylbutyrophenones when heated with zinc in ethanol.Replacement of one the aryl groups by an alkyl group strongly inhibits reaction.This effect is in part overcome by the use of a higher boiling alcohol.When substituted at the cyclopropyl methylene position by an ethoxycarbonyl group these cyclopropyl ketones also undergo cleavage but with the unexpected formation of the ethyl 3,5-diaryl-5-oxopentanoates (22).In general, the results are consistent with the formation of an anion-radical intermediate.
- Murphy, William S.,Wattanasin, Sompong
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p. 1445 - 1452
(2007/10/02)
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- Synthesis and Spectroscopic Studies of the Malonohydrazide Derivatives
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3-Aryl-1-phenyl-2-propen-1-ones (IIa-c) reacted with diethyl malonate in the presence of sodium ethoxide to give the corresponding ethyl β-aryl-γ-benzoyl-α-carbethoxybutyrate (III) which upon hydrolysis with 3percent methanolic potassium hydroxide yielded
- Al-Hajjar, Farouk H.,Al-Farkh, Yusuf A.,Al-Shamali, Fatima
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