Stereospecific Synthesis of (−)-β-Turmerone and (−)-Bisacurol

Kreiser, Wolfgang; Körner, Ferdinand

doi:10.1002/(sici)1522-2675(19991006)82:10<1610::aid-hlca1610>3.0.co;2-t

Cited by 17 publications

(17 citation statements)

References 12 publications

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“…All commercial chemicals were used as received. The following (cyclopentadienone)iron carbonyl compounds were prepared by known methods: 1 and 2 , , 3 , 4 , 5 and 6 , 7 , 8 , and 9 – 12 The following diols were prepared by known methods: racemic 17a and 18a , 23a , 29a and 33a , 30a and 32a , 31a , and 34a . Lactol 26 was prepared as a mixture of stereoisomers by diisobutylaluminium hydride (DIBAL) reduction of δ-hexalactone. , …”

Section: Methodsmentioning

confidence: 99%

(Cyclopentadienone)iron-Catalyzed Transfer Dehydrogenation of Symmetrical and Unsymmetrical Diols to Lactones

et al. 2019

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Air-stable iron carbonyl compounds bearing cyclopentadienone ligands with varying substitution were explored as catalysts in dehydrogenative diol lactonization reactions using acetone as both the solvent and hydrogen acceptor. Two catalysts with trimethylsilyl groups in the 2-and 5-positions, [2,5- 2), were found to be the most active, with 2 being the most selective in the lactonization of diols containing both primary and secondary alcohols. Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no over-oxidations to carboxylic acids were detected. The lactonization of unsymmetrical diols containing two primary alcohols occurred with catalyst 1, but selectivity was low based on alcohol electronics and modest based on alcohol sterics. Evidence for a transfer dehydrogenation mechanism was found, and insight into the origin of selectivity in the lactonization of 1°/2°diols was obtained. Additionally, spectroscopic evidence for a trimethylamine-ligated iron species formed in solution during the reaction was discovered.

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Section: Methodsmentioning

confidence: 99%

(Cyclopentadienone)iron-Catalyzed Transfer Dehydrogenation of Symmetrical and Unsymmetrical Diols to Lactones

et al. 2019

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“…and 2D NMR spectroscopy. The -turmerone and curlone steroisomers were distinguished by the 13 C NMR data [11]. NMR spectra were recorded on Avance 300 and 500 systems (Bruker, Karlsruhe, Germany).…”

Section: Methodsmentioning

confidence: 99%

Aroma of Turmeric: Dependence on the Combination of Groups of Several Odor Constituents

Hasegawa

Nakatani

Fujihara

et al. 2015

Natural Product Communications

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Turmeric is a popular material that plays an important role in the flavor and fragrance industries. Although many compounds have been reported as components of turmeric, its aroma profile has not been clarified. Recently we have developed a new approach for evaluating the complex odors of materials based on recent research on the mechanism of odor recognition. Here we report the characteristic aroma properties of turmeric obtained through the investigation of its aroma profile. The hexane extract of turmeric had a turmeric-like odor, whereas the steam distillate of turmeric had a pungent, nonturmeric-like odor. We carried out bulb-to-bulb distillations of the extract and the steam distillate. For the hexane extract, two fractions with completely different odors were obtained. One was a high boiling point fraction (group A) with a turmeric-like odor, which consisted of ar-turmerone and β-turmerone as the main components, and the other was a low boiling point fraction (group B), which consisted of α-curcumene and β-sesquiphellandrene. In contrast, the bulb-to-bulb distillation of the steam distillate gave a fraction (group C) with a very different odor from groups A and B. Group C was composed of several kinds of alcohols that were not present in groups A and B. These results indicate that the group C fraction causes the different, pungent odor of the turmeric oil obtained by steam distillation. The variation in the aroma of turmeric depended on the combination of these three groups of odor constituents.

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“…[105] Due to the importance of bisabolane derivatives, the Kreiser's research group reported in 1999 the total synthesis of their isomers starting from (À )-isopulegol 2. [106] The diastereoisomeric diol 161 d, obtained from (À )-2 in four steps with a 44 % yield, [107] was selectively monoprotected and subsequently oxidised to ketone 166 a. Protected enolisation of 166 a with LDA/Me 3 SiCl followed by bromination and subsequent elimination of HBr with collidine led to 167 a.…”

Section: Stereospecific Synthesis Of (à )-β-Turmerone and (à )-Bisacurolmentioning

confidence: 99%

Enantiomeric Isopulegol as the Chiral Pool in the Total Synthesis of Bioactive Agents

Lê

Szakonyi

2021

The Chemical Record

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Stereospecific Synthesis of (−)-β-Turmerone and (−)-Bisacurol

Cited by 17 publications

References 12 publications

(Cyclopentadienone)iron-Catalyzed Transfer Dehydrogenation of Symmetrical and Unsymmetrical Diols to Lactones

(Cyclopentadienone)iron-Catalyzed Transfer Dehydrogenation of Symmetrical and Unsymmetrical Diols to Lactones

Aroma of Turmeric: Dependence on the Combination of Groups of Several Odor Constituents

Enantiomeric Isopulegol as the Chiral Pool in the Total Synthesis of Bioactive Agents

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