Single Step Conversion of Chiral Carnitine and Derivatives into (<i>S</i>)- and (<i>R</i>)-β-Substituted-γ-Butyrolactones

Calvisi, Giuseppina; Catini, Roberto; Chiariotti, W.; Giannessi, Fabio; Muck, S.; Tinti, Maria Ornella; Angelis, Francesco De

doi:10.1055/s-1997-686

Cited by 10 publications

(7 citation statements)

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“…Purification by flash chromatography (hexanes/EtOAc, 0:100) provided the known compound 28 (4.2 g, 70%). Characterization data correlate with the previously reported data: R f = 0.28 (hexanes/EtOAc, 0:100); [α] D 25 +79 ( c = 0.9, MeOH); C 4 H 6 O 3 ; MW = 102.0886 g/mol; 1 H NMR (500 MHz, CDCl 3 ) δ 4.70–4.66 (m, 1H), 4.42 (dd, J = 10.3, 4.5 Hz, 1H), 4.30 (appd, J = 10.3 Hz, 1H), 2.86 (d, J = 3.8 Hz, 1H), 2.75 (dd, J = 17.9, 6.1 Hz, 1H), 2.52 (dd, J = 18.0, 1.0 Hz, 1H) ppm.…”

Section: Methodssupporting

confidence: 87%

Diastereoselective Synthesis of C2′-Fluorinated Nucleoside Analogues Using an Acyclic Approach

et al. 2016

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Nucleoside analogues bearing a fluorine in the C2'-position have been synthesized by S2-like cyclizations of acyclic thioaminal precursors. This strategy provides access to two scaffolds, d-1',2'-cis-thiofuranosides and d-1',2'-trans-furanosides, which are difficult to generate using the standard approach for nucleoside synthesis. The addition of silylated nucleobases onto model C2-fluorinated dithioacetal substrates resulted in 1,2-syn diastereoselectivity, which is consistent with the C2-F and S-alkyl moiety being in close proximity. A new series of analogues bearing a C3' all-carbon quaternary center along with a C2'-F atom have also been synthesized using this approach and are being investigated as potential antimetabolites.

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Section: Methodssupporting

confidence: 87%

Diastereoselective Synthesis of C2′-Fluorinated Nucleoside Analogues Using an Acyclic Approach

et al. 2016

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“…9 Other syntheses reported involve the ozonolysis of aromatic a-aminoacids 10 and the conversion of chiral carnitine and derivatives by intramolecular nucleophilic displacement in one step into 1 (R)-form, with a 77% yield. 11 As part of a program directed toward the synthesis of cross-linking monomers derived from amino acid precursors, we have developed a facile synthesis of 3-(S)-aminog-butyrolactone without any loss of optical purity. Our approach for the formation of this synthon is shown in Scheme, which involved the use of N-t-Boc-L-aspartic acid, b-benzyl ester (2) as the starting material.…”

Section: Figurementioning

confidence: 99%

Convenient Synthesis of 3-(S)-Amino-γ-butyrolactone

Sibrian‐Vazquez¹,

Spivak²

2002

Synlett

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An efficient two step conversion of N-t-Boc-L-aspartic acid b-benzyl ester to enantiopure 3-(S)-amino-g-butyrolactone is described. In this route, chemoselective reduction of the a-carboxylic group in the starting material via a mixed anhydride with NaBH 4 afforded the corresponding alcohol in 95% yield without any loss of the optical purity. Subsequent acidic hydrolysis of the Nprotected b-amino alcohol not only deprotected the amino group, but also produced the desired g-lactone in 98% yield with complete retention of the optical activity.

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“…After leaving group displacement with fluoride, the dioxanone would have been cleaved under acidic conditions restoring the -hydroxy acid. Towards this end, as shown in Scheme 3, chiral lactone 11 (commercially available or easily prepared from carnitine 26 ) was opened with sodium hydroxide 27 and directly silylated with excess TIPS-chloride to a bis-protected silyl ester and primary silyl ether for ease of chromatography and to prevent recyclization. The silyl ester was chemoselectively deprotected with simple heating in a DMF/water mixture using a strategy laid out by Chen at al.…”

Section: Syn Thesismentioning

confidence: 99%

Synthesis of 2-Fluoroacetoacetic Acid and 4-Fluoro-3-hydroxybutyric Acid

2019

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The butyric acid scaffold is the base structure of several human metabolites that serve diverse and prominent biochemical roles including as oxidative sources of cellular energy and as substrates for biosynthesis. Derivatization of metabolites through incorporation of fluorine often alters bioactivity and can facilitate detection and analysis by nuclear magnetic resonance or positron emission tomography depending upon the fluorine isotope employed. We describe the synthesis of two new fluorinated butyric acids (and three related esters) that are derivatives of the metabolites acetoacetic acid and 3-hydroxybutyric acid. 4-Fluoro-3-hydroxybutyric acid is prepared from epoxy ester precursors via ring opening by triethylamine trihydrofluoride. 2-Fluoroacetoacetic acid is prepared by electrophilic fluorination of an acid-labile β-keto ester. The gradual pH-dependent decarboxylation of 2-fluoroacetoacetic acid is investigated by 19F NMR spectroscopy.

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Single Step Conversion of Chiral Carnitine and Derivatives into (S)- and (R)-β-Substituted-γ-Butyrolactones

Cited by 10 publications

References 0 publications

Diastereoselective Synthesis of C2′-Fluorinated Nucleoside Analogues Using an Acyclic Approach

Diastereoselective Synthesis of C2′-Fluorinated Nucleoside Analogues Using an Acyclic Approach

Convenient Synthesis of 3-(S)-Amino-γ-butyrolactone

Synthesis of 2-Fluoroacetoacetic Acid and 4-Fluoro-3-hydroxybutyric Acid

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Single Step Conversion of Chiral Carnitine and Derivatives into (S)- and (R)-β-Substituted-γ-Butyrolactones

Cited by 10 publications

References 0 publications

Diastereoselective Synthesis of C2′-Fluorinated Nucleoside Analogues Using an Acyclic Approach

Diastereoselective Synthesis of C2′-Fluorinated Nucleoside Analogues Using an Acyclic Approach

Convenient Synthesis of 3-(S)-Amino-γ-butyrolactone

Synthesis of 2-Fluoroacetoacetic Acid and 4-Fluoro-3-hydroxy­butyric Acid

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Synthesis of 2-Fluoroacetoacetic Acid and 4-Fluoro-3-hydroxybutyric Acid