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Enantioselective Organocatalysis-Based Synthesis of 3-Hydroxy Fatty Acids and Fatty γ-Lactones

by Asimina Bourboula, Dimitris Limnios, Maroula G. Kokotou, Olga G. Mountanea and George Kokotos

Molecules 2019, 24(11), 2081; https://doi.org/10.3390/molecules24112081 - 31 May 2019

Cited by 11 | Viewed by 5396

3-Hydroxy fatty acids have attracted the interest of researchers, since some of them may interact with free fatty acid receptors more effectively than their non-hydroxylated counterparts and their determination in plasma provides diagnostic information regarding mitochondrial deficiency. We present here the development of a convenient and general methodology for the asymmetric synthesis of 3-hydroxy fatty acids. The enantioselective organocatalytic synthesis of terminal epoxides, starting from long chain aldehydes, is the key-step of our methodology, followed by ring opening with vinylmagnesium bromide. Ozonolysis and subsequent oxidation leads to the target products. MacMillan’s third generation imidazolidinone organocatalyst has been employed for the epoxide formation, ensuring products in high enantiomeric purity. Furthermore, a route for the incorporation of deuterium on the carbon atom carrying the hydroxy group was developed allowing the synthesis of deuterated derivatives, which may be useful in biological studies and in mass spectrometry studies. In addition, the synthesis of fatty γ-lactones, corresponding to 4-hydroxy fatty acids, was also explored. Full article

(This article belongs to the Section Organic Chemistry)

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14 pages, 8069 KB

Open AccessArticle

Regioselectivity in Reactions between Bis(2-benzothiazolyl)ketone and Vinyl Grignard Reagents: C- versus O-alkylation—Part III

by Carla Boga, Silvia Bordoni, Lucia Casarin, Gabriele Micheletti and Magda Monari

Molecules 2018, 23(1), 171; https://doi.org/10.3390/molecules23010171 - 15 Jan 2018

Cited by 4 | Viewed by 6365

Abstract

The reaction between bis(2-benzothiazolyl)ketone and vinyl Grignard reagents bearing different substituents on the vinyl moiety gave the product derived from attack on the carbonylic carbon- and/or oxygen-atom. The regioselectivity of the attack depends on the kind of substituents bound to the vinylic carbon atoms and on their relative position. The reaction between vinylmagnesium bromide and 2-methyl-1-propenylmagnesium bromide was carried out under different experimental conditions and in the presence of radical scavengers. The results indicate a plausible mechanistic pathway involving radical intermediates in the case of O-alkylation, but a polar ones in the case of classic C-alkylation. This agrees with our previous reports indicating a key role played by the delocalization ability of the substituents bound to the carbonyl group in driving the regioselectivity of the vinylmagnesium bromide attack towards O-alkylation. Further support of this was obtained by diffractometric analysis of four distinct bis(heteroaryl)ketones. Full article

(This article belongs to the Collection Heterocyclic Compounds)

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1 pages, 74 KB

Open AccessShort Note

5-Methoxy-7,7-dimethyl-1,9(E),11-dodecatrien-3-ol

by Douglas A. Smith

Molecules 1997, 2(10), M37; https://doi.org/10.3390/M37 - 31 Oct 1997

Cited by 1 | Viewed by 3606

Abstract

To a stirred solution of the diene aldehyde [1] in dry THF under Ar at -78 ƒC, vinylmagnesium bromide in THF was added via a syringe.[...] Full article

(This article belongs to the Section Molbank Section of Molecules, 1997-2001)

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