Direct α-hydroxylation of ketones under acidic conditions using [bis (trifluoroacetoxy)] iodobenzene

Moriarty, Robert M.; Berglund, Bruce; Penmasta, Raju

doi:10.1016/s0040-4039(00)60007-2

Cited by 99 publications

(47 citation statements)

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“…The isolation of pure products was carried out via thin layer chromatography (silica gel 60 GF 254 , Merck). Except for 1-hydroxyhexan-2-one (2l), which was prepared by selective oxidation of diols [29], all a-hydroxyketones were synthesized by direct a-hydroxylation of ketones with [bis(trifluoroacetoxy)iodo]benzene and trifluoroacetic acid [30] as well as a-bromination of of ketones followed by hydroxylation [31,32]. Commercially available organic and inorganic compounds were used without further purification.…”

mentioning

confidence: 99%

A recyclable copper catalysis in quinoxaline synthesis from α-hydroxyketones and o-phenylenediamines

Cho

Ren

2009

Journal of Organometallic Chemistry

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mentioning

confidence: 99%

A recyclable copper catalysis in quinoxaline synthesis from α-hydroxyketones and o-phenylenediamines

Cho

Ren

2009

Journal of Organometallic Chemistry

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“…82.5-83.2˚C; Lit. : 83-84.5˚C (Miller & Cantor, 1952), was synthesized from 2-acetylfuran by the procedure described by Moriarty et al (1992).…”

Section: Methodsmentioning

confidence: 99%

Determination of Reductones, Furans and Organic Acids in Aqueous Model Matrices Using Solid-Phase Extraction and Gas Chromatography/Mass Spectrometry

Mori

Ito

2004

FSTR

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A method using solid-phase extraction (SPE) and GC-MS was developed for the determination of a series of polar and unstable flavor compounds: reductones, furans and volatile organic acids, in aqueous model matrices. The SPE procedures were optimized mainly on the pH-dependency of the analytes with regard to their adsorption characteristics. Good recovery of the reductones except DDMP was obtained at pH 2 and 4.5. Furan derivatives were generally recovered in high yields under the acidic to neutral pH conditions examined. All organic acids were recovered almost quantitatively at pH 2. An essentially comparable result was obtained in a model Maillard reaction mixture. In order to apply this method to alcoholic beverages, effect of the ethanol concentration on the SPE adsorption of the analytes was also investigated.Keywords: solid-phase extraction (SPE), gas chromatography/mass spectrometry (GC-MS), reductone, furan, organic acid Reductones, furans (Ledl & Schleicher, 1990) and organic acids (Hofmann et al., 2000) are commonly found in foods and beverages. Most reductones and volatile acids exhibit important sensory properties with low threshold values, and some of them are utilized as food flavors. Furan derivatives generated from sugars by non-enzymatic browning are closely related to the chemical changes in foods and beverages during their processing and storage (Lee & Nagy, 1990).Such types of compounds have relatively high polarity and ionic characters, so that their high water solubility results in low recovery in conventional solvent-extraction methods. Headspace sampling and solid-phase microextraction (SPME) are frequently used for the selective extraction of volatile flavors from a complex matrix. Unfortunately, the main disadvantage of these methods is low recovery of polar analytes (Pan et al., 1995).In addition, reductones and furans tend to be decomposed during the analytical procedures, particularly at the elevated temperature used in GC analysis (Blank et al., 1992). To compensate for losses during the workup procedure for GC analysis, stable isotope dilution assays (Sen et al., 1991) were developed. However, this technique requires the corresponding isotope-labeled derivative of each analyte as the internal standard.Column adsorption (Shimoda et al., 1987) and solid phase extraction (SPE) (Coulibaly & Jeon, 1996) are now widely used for the extraction and clean up of flavor compounds in foods and beverages. Even though some efficient methods had been developed for the analysis of reductones, most of them were optimized to one or a few analytes on high performance liquid chromatography (HPLC) (Walsh et al., 1997). The HPLC methods are not suitable to trace level multiple analytes.To our knowledge, there were only a few reports concerning the GC-quantitation of such polar and unstable volatiles from aqueous matrices using SPE treatments (Wada & Shibamoto, 1997;Adahchour et al., 1999). Recently, Thum and Back (1999) applied their SPE procedure for a selective concentration of a series of aroma compou...

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“…The transformation can be achieved using PIFA and trifluoroacetic acid, 117 or with the iodine(V) reagent IBX. 113b,118 Trimethylsilyl enol ethers can be a-methoxylated with PhIO activated by BF 3 in methanol (Scheme 46(c)).…”

Section: Acyloxylation Hydroxylation and Methoxylationmentioning

confidence: 99%

7.07 α-Oxygenation of Carbonyl Compounds

Bouma

Olofsson

2014

Comprehensive Organic Synthesis II

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Direct α-hydroxylation of ketones under acidic conditions using [bis (trifluoroacetoxy)] iodobenzene

Cited by 99 publications

References 45 publications

A recyclable copper catalysis in quinoxaline synthesis from α-hydroxyketones and o-phenylenediamines

A recyclable copper catalysis in quinoxaline synthesis from α-hydroxyketones and o-phenylenediamines

Determination of Reductones, Furans and Organic Acids in Aqueous Model Matrices Using Solid-Phase Extraction and Gas Chromatography/Mass Spectrometry

7.07 α-Oxygenation of Carbonyl Compounds

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