A new synthesis of 3-n-butyl-4-bromo-5(Z)-bromomethylidene-2(5H)-furanone, a naturally occurring fimbrolide from Delisia fimbriata (Bonnemaisoniaceae)

Caine, Drury; Ukachukwu, Victoria C.

doi:10.1021/jo00212a040

Cited by 30 publications

(16 citation statements)

References 7 publications

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“…A reinvestigation of this reaction revealed it not only yields the natural furanone 2 but also significant amounts of isomeric 3-butyl-5-dibromoseemingly harsh conditions of concentrated sulphuric acid at elevated temperature. Caine and Ukachukwu (1985) also developed an elegant synthesis of 4-bromo-3-butyl-5-bromomethylene-2(5H)-furanone via the reaction of (E)-β-bromo-β-lithioacrylates with acetic anhydride to form 5-hydroxy-5-methyl-4-bromo-3-butyl-2(5H)-furanone in high yield which could be further transformed into the desired bromomethylene compound. However, these syntheses provide a limited basis for the development of metabolites as they only addressed the synthesis of the unsubstituted furanones.…”

Section: Chemical Synthesismentioning

confidence: 99%

Antifouling Compounds

2006

Marine Molecular Biotechnology

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Section: Chemical Synthesismentioning

confidence: 99%

Antifouling Compounds

2006

Marine Molecular Biotechnology

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“…Acrylic acid derivatives with a heteroatom (N, O, S, Hal) at C-3 can be cleanly deprotonated at this position with BuLi or LDA at low temperatures [329,[333][334][335][336][337][338] (Scheme 5.37). Some of these anions rearrange to the a-metalated acrylates on warming [329], but can also decompose (see Section 5.4.7).…”

Section: Vinylic Carbanionsmentioning

confidence: 99%

The Alkylation of Carbanions

Dörwald

2004

Side Reactions in Organic Synthesis

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The deprotonation of organic compounds by strong, non-nucleophilic bases followed by C-alkylation with a suitable electrophile has become one of the most predictable and straightforward methods for formation of C-C bonds. The popularity of this chemistry is also a consequence of the often-seen close resemblance of feasible structural modifications by a deprotonation/alkylation strategy to an unsophisticated retrosynthetic analysis of a given target compound. Other reactions, which involve, for instance, substantial rearrangement of the carbon framework (e.g. Cope rearrangement, fragmentations, ring contractions or enlargements) are usually more difficult to take into account during retrosynthetic analysis.LDA and related, sterically hindered, lithium dialkylamides, first investigated by Levine [1], have completely replaced the more nucleophilic sodium amide, which had been the base of choice for many years [2]. Because the reactivity of an organometallic compound depends to a large extent on its state of aggregation (i.e. on the solvent and on additives) and on the metal, transmetalation of the lithiated intermediates and the choice of different solvents and additives emerged as powerful strategies for fine-tuning the reactivity of these valuable nucleophiles.In this chapter the alkylation of carbanions with simple carbon electrophiles will be discussed, with special emphasis on the structure-reactivity relationship of the carbanion and on side reactions. In this context the term "carbanion" refers to an intermediate prepared by in-situ deprotonation of an organic compound, followed by optional cation exchange (transmetalation), which tends to be alkylated at carbon by soft electrophiles such as MeI or PhCHO. This type of reactivity is characteristic of enolates with an ionic M-O bond or for organometallic compounds with a strongly polarized or ionic M-C bond, M typically being an alkali metal, Mg, Cu, or Zn. Carbanions can, alternatively, also be prepared by halogen-metal exchange [3-8], sulfoxide-or sulfone-metal exchange [9-13], or by transmetalation of stannanes. The most suitable reagents for performing such metalating exchange reactions are organometallic compounds with a metal-bound secondary or tertiary alkyl group, such as tBuLi, sBuLi, iPr 2 Zn [14, 15], or iPrMgHal [6]. These reagents are thermodynamically less stable than organometallic compounds with primary alkyl 5 146 Scheme 5.1. Approximate relative rates of proton transfer in water at thermoneutrality (DpK a = 0) [35, 39, 51]. 147 Scheme 5.2. The effect of fluorine on the acidity of organic compounds [24, 62-65]. 148 Scheme 5.3. Dependence of the reactivity of carbanions on their basicity [68, 72-74]. Regioselectivity of Deprotonations and AlkylationsThe organic chemist is occasionally confronted with the problem that a compound has several differrent X-H groups of similar pK a . If only one of these is to be alkylated, one option would be to perform a regioselective deprotonation. This can sometimes be achieved by exploiting small differences be...

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“…5 Dentre as furanonas bioativas que apresentam comprovada atividade antimicrobiana destacam-se as furanonas pertencentes à classe dos g-alquilidenobutenolídeos (Figura 1). [6][7][8][9][10][11] Diversos estudos mostraram que furanonas bromadas inibem a formação de biofilmes em várias espécies de bactérias. 12 As substâncias conhecidas como fimbrolídeos (1), isoladas da alga vermelha Delisea pulchra, são inibidoras da formação de biofilmes em Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Staphylococcus epideridis e Streptococcus ssp.…”

Section: Introductionunclassified

Síntese e avaliação da atividade antimicrobiana de furanonas halogenadas e de compostos análogos aos nostoclídeos

Barbosa¹,

Maltha²,

Demuner³

et al. 2010

Quím. Nova

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Recebido em 22/2/10; aceito em 5/8/10; publicado na web em 25/10/10 SYNTHESIS AND EVALUATION OF ANTIMICROBIAL ACTIVITY OF HALOGENATED FURANONES AND COMPOUNDS ANALOGUES TO NOSTOCLIDES. Considering the broad spectrum of biological activity of gamma-butyrolactone derivatives, we presented the synthesis of 3,4-dihalo-5-arylidenefuran-2(5H)-ones (17-21) and analogues (24-28) of the natural product nostoclide (7,8). Furanones 17-21 were synthesized from the condensation of aromatic aldehydes with lactones 14 and 15, that were obtained from mucobromic and mucochloric acids. Lactone 15 was converted into the intermediate 23 in 36% overall yield. Compound 23 was then transformed into the nostoclide analogues 24-28. Some of the compounds prepared showed antimicrobial activities against Escherichia coli, Staphylococcus aureus and Bacillus cereus comparable to commercial antibiotics.

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A new synthesis of 3-n-butyl-4-bromo-5(Z)-bromomethylidene-2(5H)-furanone, a naturally occurring fimbrolide from Delisia fimbriata (Bonnemaisoniaceae)

Abstract: Entsprechend dem Formelschema werden aus dem Ester (I) die im Titel genannte Verbindung (VI) und das Dichlor‐Derivat (VIII) dargestellt.

Cited by 30 publications

References 7 publications

Antifouling Compounds

Antifouling Compounds

The Alkylation of Carbanions

Síntese e avaliação da atividade antimicrobiana de furanonas halogenadas e de compostos análogos aos nostoclídeos

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