Two new butanolides from the roots of Litsea acuminata

Tanaka, Hitoshi; Takaya, Yoshiaki; Toyoda, Junya; Yasuda, Tadashi; Satô, Masaru; Murata, Jin; Murata, Hiroko; Kaburagi, K; Iida, Osamu; Sugimura, Koji; Shimizu, Eiji

doi:10.1016/j.phytol.2014.11.001

Cited by 16 publications

(32 citation statements)

References 15 publications

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“…To our disappointment, this substrate failed to deliver the expected dyotropic rearrangement product. Instead, ent ‐licunolide A ( 95 b ) [33] was obtained as major product, apparently through the deprotection of TBS group followed by intramolecular transesterification reaction [13, 34] . Of note, the absolute stereochemistry of 95 b is identical to another natural product 3‐ epi ‐litsenolide D2 [32] …”

Section: Resultsmentioning

confidence: 99%

Strain‐Driven Dyotropic Rearrangement: A Unified Ring‐Expansion Approach to α‐Methylene‐γ‐butyrolactones

Lei

Lai

et al. 2020

Angew Chem Int Ed

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An unprecedented strain‐driven dyotropic rearrangement of α‐methylene‐β‐lactones has been realized, which enables the efficient access of a wide range of α‐methylene‐γ‐butyrolactones displaying remarkable structural diversity. Several appealing features of the reaction, including excellent efficiency, high stereospecificity, predictable chemoselectivity and broad substrate scope, render it a powerful tool for the synthesis of MBL‐containing molecules of either natural or synthetic origin. Both experimental and computational evidences suggest that the new variant of dyotropic rearrangements proceed in a dualistic pattern: while an asynchronous concerted mechanism most likely accounts for the reactions featuring hydrogen migration, a stepwise process involving a phenonium ion intermediate is favored in the cases of aryl migration. The great synthetic potential of the title reaction is exemplified by its application to the efficient construction of several natural products and relevant scaffolds.

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Section: Resultsmentioning

confidence: 99%

Strain‐Driven Dyotropic Rearrangement: A Unified Ring‐Expansion Approach to α‐Methylene‐γ‐butyrolactones

Lei

Lai

et al. 2020

Angew Chem Int Ed

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“…Thus, the Δ 2(6) double bond has an E configuration in 3 , rather than the Z configuration in miaolinolide [29]. This assignment was also proved that the chemical shift of H-6 in 3 was close to that of related butanolides with an E configuration of the Δ 2(6) double bond [15,25,26,30], including compounds 1 and 2 . A NOESY correlation between H-3 and H-7 (Figure 3) supported this conclusion.…”

Section: Resultsmentioning

confidence: 79%

Isolation, Structure Elucidation, and Antiproliferative Activity of Butanolides and Lignan Glycosides from the Fruit of Hernandia nymphaeifolia

et al. 2019

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Seven new butanolides, peltanolides A–G (1–7), and two lignan glucosides, peltasides A (8) and B (9), along with eleven known compounds, 10–20, were isolated from a crude CH3OH/CH2Cl2 (1:1) extract of the fruit of Hernandia nymphaeifolia (Hernandiaceae). The structures of 1–9 were characterized by extensive 1D and 2D NMR spectroscopic and HRMS analysis. The absolute configurations of newly isolated compounds 1–9 were determined from data obtained by optical rotation and electronic circular dichroism (ECD) exciton chirality methods. Butanolides and lignan glucosides have not been isolated previously from this genus. Several isolated compounds were evaluated for antiproliferative activity against human tumor cell lines. Lignans 15 and 16 were slightly active against chemosensitive tumor cell lines A549 and MCF-7, respectively. Furthermore, both compounds displayed significant activity (IC50 = 5 µM) against a P-glycoprotein overexpressing multidrug-resistant tumor cell line (KB-VIN) but were less active against its parent chemosensitive cell line (KB).

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“…[34] Asubsequent Wittig reaction under Bodensc onditions [35] furnished rosefuran in 97 % yield. To prevent complications resulting from lithiation of the free C5 position of 4,w ec hose KOtBu as the base.W e used the same approach for the syntheses of sesquirosefuran [36] and mikanifuran. [37] In these cases,e xcess ketone and high reaction concentrations were necessary to prevent the formation of 3-methyl-2-vinylfuran as as ide product (presumably resulting from E2 elimination of 4).…”

Section: Resultsmentioning

confidence: 99%

“…[6a,b] While mikanifuran has no known biological activity,sesquirosefuran displays significant cytotoxicitya gainst HeLa cells in vivo. [36] Thec ommercial importance and biological activity of rosefuran has inspired several ingenious syntheses of it and related furanoterpenes.These strategies can be classified into alkylation, transition metal-catalyzed methods,functionalization of cyclic precursors,a nd cyclization of linear precursors. [41] Fort he total synthesis of 3D5,aunique F-acid found in the soft corals S. glaucum and S. gemmatun (Scheme 2C), we employed as equence of reduction, Appel reaction, and cyanation of the furan 3ll to produce the nitrile 5,w hich…”

Section: Resultsmentioning

confidence: 99%

Unified Approach to Furan Natural Products via Phosphine‐Palladium Catalysis

Chen

Kwon

2021

Angewandte Chemie

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Polyalkyl furans are widespread in nature,o ften performing important biological roles.D espite ap lethora of methods for the synthesis of tetrasubstituted furans,t he construction of tetraalkylf urans remains non-trivial. The prevalence of alkylgroups in bioactive furan natural products, combined with the desirable bioactivities of tetraalkylf urans, calls for ageneral synthetic protocol for polyalkylfurans.This paper describes aM ichael-Heck approach, using sequential phosphine-palladium catalysis,f or the preparation of various polyalkylf urans from readily available precursors.T he versatility of this method is illustrated by the total syntheses of nine distinct polyalkylated furan natural products belonging to different classes,n amely the furanoterpenes rosefuran, sesquirosefuran, and mikanifuran;the marine natural products plakorsins A, B, and Dand plakorsin Dmethyl ester;and the furan fatty acids 3D5 and hydromumiamicin.

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Two new butanolides from the roots of Litsea acuminata

Cited by 16 publications

References 15 publications

Strain‐Driven Dyotropic Rearrangement: A Unified Ring‐Expansion Approach to α‐Methylene‐γ‐butyrolactones

Strain‐Driven Dyotropic Rearrangement: A Unified Ring‐Expansion Approach to α‐Methylene‐γ‐butyrolactones

Isolation, Structure Elucidation, and Antiproliferative Activity of Butanolides and Lignan Glycosides from the Fruit of Hernandia nymphaeifolia

Unified Approach to Furan Natural Products via Phosphine‐Palladium Catalysis

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