Synthesis of the indole nucleoside antibiotics neosidomycin and SF-2140

Buchanan, J. G.; Stoddart, Jane; Wightman, R. H.

doi:10.1039/p19940001417

Cited by 19 publications

(11 citation statements)

References 20 publications

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“…From a synthetic viewpoint, this reaction gives a highly efficient access to indole N -glycosides when combined with a metal-catalyzed ring-closing-metathesis (RCM) reaction. Indole glycosides such as ribofuranosyl indoles and neosidomycin have received considerable attention because of their unique biological activities. Because of the low nucleophilicity of indole nitrogen, synthesis of this type of compound in many cases relies on the indirect method using more reactive indoline nucleophile and the subsequent dehydrogenation.…”

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confidence: 99%

Palladium-Catalyzed Asymmetric Nitrogen-Selective Addition Reaction of Indoles to Alkoxyallenes

et al. 2018

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A new palladium-catalyzed asymmetric addition reaction of indoles to alkoxyallenes is reported. Remarkably, the reaction showed complete regioselectivity toward the nitrogen. A new mechanism distinct from that of conventional π-allyl chemistry is proposed to explain this unique selectivity. The utility of the reaction is demonstrated by highly efficient and flexible synthesis of N-glycosylindoles.

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confidence: 99%

Palladium-Catalyzed Asymmetric Nitrogen-Selective Addition Reaction of Indoles to Alkoxyallenes

et al. 2018

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“…There are three other members of this family of indole- N -glycosyls ( 6 – 8 , Figure ), , and these molecules possess antibacterial or antiviral activities. Only one synthesis of neosidomycin 5 has been previously described (as an inseparable anomeric mixture of products), and the chiron approach was used for the preparation of the carbohydrate moiety . Our retrosynthetic analysis shows that compound 5 could be made by coupling of a glycosyl donor with indole 30 (Figure ).…”

Section: Resultsmentioning

confidence: 95%

“…First of all, Wightman’s synthesis of neosidomycin 5 relied on O-4 deoxygenation of an orthogonally protected mannoside, followed by oxidation at the C-6 position. , In opposition, we believe the synthesis could be shortened by first oxidizing C-6 followed by O-4 deoxygenation of a suitable mannoside derivative.…”

Section: Resultsmentioning

confidence: 99%

“…Removal of the O-4 hydroxyl group was achieved in a classical manner through formation of thiocarbonyl 33 in 63% yield, followed by a radical deoxygenation using AIBN and Bu 3 SnH in 62% yield. The derivative methyl 4-deoxy-β- d - lyxo -uronate 34 was deprotected under acidic conditions ( 35 ) and suitably protected with PivCl in 91% yield, affording the known compound 36 …”

Section: Resultsmentioning

confidence: 99%

“…The α configuration was determined by direct NMR coupling of the anomeric proton and carbon (91.3 ppm, 1 J C–H = 177.8 Hz) . This compound was previously described by the Wightman group ( 39 : nine steps, 20% yield), and our strategy ( 39 : eight steps, 26% yield) represents a slightly improved synthesis using a new chiron approach, both methods from methyl α- d -mannopyranoside 31 . Finally, the preparation of a halogenated glycosyl donor was achieved by treating compound 39 in a mixture of HBr 33% in acetic acid, affording the unstable α-bromo compound 40 in quantitative yield.…”

Section: Resultsmentioning

confidence: 99%

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Enantioselective de Novo Synthesis of 4-Deoxy-d-hexopyranoses via Hetero-Diels–Alder Cycloadditions: Total Synthesis of Ezoaminuroic Acid and Neosidomycin

et al. 2011

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The de novo synthesis of carbohydrates constitutes an important aspect of organic chemistry, and its application toward deoxy sugars is particularly noteworthy in targeting biologically active compounds. The enantioselective preparation of 4-deoxy-D-ribo-, 4-deoxy-D-lyxo-, and 4-deoxy-D-xylo-hexopyranosides, along with their uronate counterparts has been successfully accomplished using hetero-Diels-Alder reactions as the key step. Jacobsen chromium(III) catalyst and a titanium-binaphthol complex have been used to successfully catalyze diene and aldehyde cycloadditions, leading to optically active dihydropyran templates. 6-Hydroxydesosamine, orthogonally protected ezoaminuroic acid, and neosidomycin were synthesized using a comparative study. Also, a novel chiron approach to 4-deoxy-lyxo-hexopyranosiduronic acid methyl ester derivatives was efficiently accomplished starting from readily accessible starting materials. This work represents a systematic and comprehensive study toward a de novo synthesis of 4-deoxy-hexopyranoses via enantioselective hetero-Diels-Alder reactions.

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Synthesis Of Nucleosides

Vorbrüggen¹,

1999

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This chapter deals with the synthesis of nucleosides (e.g., the formation of N ‐glycosides of sugars such as D ‐ribose or 2‐deoxy‐D‐ribose with heterocyclic nitrogen bases). The methods of nucleoside synthesis have been treated in a number of reviews and monographs. It is now generally accepted that nucleosides were among the first organic compounds formed at the start of evolution in the early history of our planet earth. To support this point, guanine and adenine were heated with D ‐ribose in seawater, which contains the Lewis acid magnesium chloride as catalyst. One thus obtained the nucleosides guanosine and adenosine together with comparable yields of unnatural α‐nucleosides. The latter were gradually photoanomerized to the thermodynamically more stable compounds in overall yields of 5–6%. The furanose form of ribose reacts faster than the pyranose form. Corresponding syntheses of the pyrimidine nucleosides uridine and cytidine from uracil , cytosine and ribose are more problematic and remain an enigma. The recent conversion of glycolaldehyde‐ O ‐phosphate and formaldehyde to ribose‐2,4‐di‐ O ‐phosphate might give new insights into the prebiotic syntheses of uridine and cytidine. The evidence and hypotheses for these prebiotic conversions and the evolution of RNA, as well as the implications of an “RNA World,” have been reviewed. These RNA nucleosides are reduced in vivo as 5′‐ O ‐diphosphates by ribonucleotide reductases to the corresponding 2′‐deoxynucleosides—the building blocks of DNA such as 2′‐deoxyguanosine. The thermodynamically controlled synthesis of these four building blocks of RNA has implications for the design of efficient, high yielding, new methods for the synthesis of the naturally occurring nucleosides, nucleoside antibiotics, and modified nucleosides that may serve as antimetabolites to fight viral and parasitic diseases and cancer. The nucleoside rings in this chapter are depicted arbitrarily in the anti conformation, as occurs predominantly in the crystal and solution (based primarily on NOE‐ 1 H‐ and 13 C‐NMR measurements) forms of pyrimidine nucleosides. Only a few nucleosides, such as 6‐methyluridine, occur with the heterocyclic ring predominantly in the syn conformation. The synthesis of C ‐nucleosides has been reviewed previously and is not covered in this review.

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Synthesis of the indole nucleoside antibiotics neosidomycin and SF-2140

Cited by 19 publications

References 20 publications

Palladium-Catalyzed Asymmetric Nitrogen-Selective Addition Reaction of Indoles to Alkoxyallenes

Palladium-Catalyzed Asymmetric Nitrogen-Selective Addition Reaction of Indoles to Alkoxyallenes

Enantioselective de Novo Synthesis of 4-Deoxy-d-hexopyranoses via Hetero-Diels–Alder Cycloadditions: Total Synthesis of Ezoaminuroic Acid and Neosidomycin

Synthesis Of Nucleosides

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