- One-Pot Synthesis of 2,5-Disubstituted Furans through In Situ Formation of Allenes and Enolization Cascade
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A one-pot synthesis of 2,5-disubstituted furans from γ-ketoacids is reported. In situ formation of allenoates by action of chloroformate on carboxylic acid following by enolization of ketone affords furan derivatives by cyclization. The reaction was extended to a wide scope of ketoacids and phosphonium salts. This methodology was applied on levulinic acid and derivatives, one of the biosourced platform chemicals.
- Bernhard, Yann,Gilbert, Joachim,Bousquet, Till,Favrelle-Huret, Audrey,Zinck, Philippe,Pellegrini, Sylvain,Pelinski, Lydie
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- A Radical-Based Synthesis of Lingzhiol
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The polycyclic natural product lingzhiol [(±)-1] was synthesized from dimethoxytetralone 8 via cyclization of an intermediate benzylic radical, generated from spiroepoxide 14, onto an alkynyl substituent generating tetracyclic compound 13 with an exocyclic double bond. After oxidative cleavage of the double bond of 13 and reduction of the keto function of 23, the correct diastereomer, 12-syn, was converted to lingzhiol (1) via known steps. In a similar manner, lingzhiol analogue 39 was synthesized from 5-methoxy-1-tetralone (27).
- Mehl, Lea-Marina,Maier, Martin E.
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p. 9844 - 9850
(2017/09/23)
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- Rapid probing of the reactivity of P450 monooxygenases from the CYP116B subfamily using a substrate-based method
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Developing a detailed understanding of the reactivity of self-sufficient Type IV P450 monooxygenases, four types of O-methylated substrates were designed as probes, including monoterpenes, cycloalkanes, aromatic compounds and steroids, and the efficiency of their oxyfunction was determined using a colorimetric assay which was based on the reaction between the enzymatic demethylation product, formaldehyde, and Purpald dye. The activity-based fingerprints of new P450RpMO, P450ArMO and P450CtMO (CYP116B members) indicated that CYP116B P450s preferentially oxidize substrates with aromatic components. Moreover, the hydroxylated products were detected based on the preference results. This rapid and efficient strategy, when coupled with GCMS, enables the exploration of the reactivity of other CYP116B members.
- Li, Ren-Jie,Xu, Jian-He,Yin, Yue-Cai,Wirth, Nicolas,Ren, Jiang-Meng,Zeng, Bu-Bing,Yu, Hui-Lei
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supporting information
p. 8928 - 8934
(2016/10/13)
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- Enzymatic synthesis of chiral γ-amino acids using ω-transaminase
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In this study, we successfully synthesized enantiomerically pure (R)- and (S)-γ-amino acids (>99% ee) using ω-transaminase (ω-TA) through kinetic resolution and asymmetric synthesis respectively. The present study demonstrates the high potentiality of ω-TA reaction for the production of chiral γ-amino acids.
- Shon, Minsu,Shanmugavel, Ramachandran,Shin, Giyoung,Mathew, Sam,Lee, Sang-Hyeup,Yun, Hyungdon
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supporting information
p. 12680 - 12683
(2015/05/20)
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- Design and synthesis of 4-aryl-4-oxobutanoic acid amides as calpain inhibitors
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The involvement of μ-calpain in neurological disorders, such as stroke and Alzheimer's disease has attracted considerable interest in the use of calpain inhibitors as therapeutic agents. 4-Aryl-4-oxobutanoic acid amide derivatives 4 were designed as acyclic variants of μ-calpain inhibitory chromone and quinolinone derivatives. Of the compounds synthesized, 4c-2, which possesses a 2-methoxymethoxy group at the phenyl ring and a primary amide at the warhead region most potently inhibited μ-calpain (IC50 = 0.34 μM). Our findings suggest that the 4-aryl-4-oxobutanoic acid amide derivatives should be considered as a new family of μ-calpain inhibitors.
- Zhang, Yong,Jung, Seo Yoon,Jin, Changbae,Kim, Nam Doo,Gong, Ping,Lee, Yong Sup
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scheme or table
p. 502 - 507
(2011/02/28)
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- Synthesis of Methoxy-2-hydroxy-1,4-naphthoquinones and Reaction of One Isomer with Aldehydes under Basic Conditions
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Two protocols for the synthesis of methoxy-2-hydroxy-1,4-naphthoquinones were investigated in order to evaluate their behavior towards aldehydes under amine-basic conditions. Both the nature of the quinone and aliphatic aldehyde contribute to the viability of this condensation as well as further transformations.
- Ameer, Farouk,Giles, Robin G. F.,Green, Ivan R.,Pearce, Rene
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p. 1247 - 1258
(2007/10/03)
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- Direct synthesis of γ-butyrolactones via γ-phenyl substituted butyric acids mediated benzyl radical cyclization
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Synthesis of several γ-butyrolactones with aromatic substitution at carbon 5 from comparative γ-aryl acids with 25-85% yield are covered. The straight oxidation in the presence of peroxydisulphate-copper(II)chloride system in aqueous medium was applied. The reaction is highly regioselective and leads exclusively to γ-butyrolactone, through stable benzylic radical intermediate.
- Mahmoodi,Jazayri
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p. 1467 - 1475
(2007/10/03)
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- Formal total synthesis of (+)-diepoxin σ
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The highly oxygenated antifungal anticancer natural product (±)-diepoxin σ was prepared in 10 steps and in 15% overall yield from O-methylnaphthazarin. Highlights of the synthetic work include an Ullmann coupling and a possibly biomimetic oxidative spirocyclization for the introduction of the naphthalene ketal as well as the use of a retro-Diels-Alder reaction to unmask the reactive enone moiety in the naphthoquinone bisepoxide ring system. A novel highly bulky chiral binaphthol ligand was developed for a boron-mediated Diels-Alder reaction that constitutes a formal asymmetric total synthesis of (+)-diepoxin σ.
- Wipf, Peter,Jung, Jae-Kyu
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p. 6319 - 6337
(2007/10/03)
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- Asymmetric synthesis and antitumor activity of cycloalkanin
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Cycloalkanin was accessible by a practical and efficient asymmetric synthesis. The chiral center of the target is introduced via an asymmetric C-arylation of chiral aldehyde in high de. The synthesized cycloalkanin was shown to be significantly active against P388 cell line as assayed by in vitro MTT method.
- Wu, Xihan,Xu, Liang,Cai, Junchao
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p. 2635 - 2638
(2007/10/03)
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- A Direct Route for the Regioselective Synthesis of Hydroxylated Aromatic Cycloalkanediones
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A "one-pot" regioselective synthesis of hydroxylated aromatic cycloalkanediones 1 from phenols or their methyl ethers and aliphatic dicarboxylic acid chlorides is reported.
- Sartori, Giovanni,Bigi, Franca,Goffredi, Gino,Maggi, Raimondo,Portioli, Roberto,Casnati, Giuseppe
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p. 2061 - 2079
(2007/10/02)
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- Anodic Oxidation as a Synthetic Expedient to Naphthoquinone and Anthraquinone Ketals
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Some naphthoquinone and anthraquinone ketals have been prepared by anodic oxidation.Regioselective hydrolysis of the above diketals into monoketals is also described.Diels-Alder reaction of (E)-1-methoxybuta-1,3-diene with the monoketal of 1,4-dihydro-4,4-dimethoxy-5-benzyloxynaphthalene proceeded in a regioselective manner. Key words: naphthoquinone ketals, anthraquinone ketals, regioselective hydrolysis, Diels-Alder reaction.
- Yang, Zhen,Cui, Yu Xin,Wong, Henry N. C.,Wang, Ru Ji,Mak, Thomas C. W.,et al.
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p. 3293 - 3302
(2007/10/02)
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- Metal-assisted cyclization of alkynols at a d6 metal template: One-pot synthesis of 2-oxacycloalkylidene complexes of chromium, tungsten, and manganese
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The photoinduced decarbonylation of Cr(CO)6, W(CO)6, and (η5-C5H4CH3)Mn(CO)3 in ether is exploited in the metal-assisted cyclization of alkynols HC≡C(CH2)nOH (n = 2, 3) leading to 2-oxacycloalkylidene complexes L(CO)2M[=CO(CH2)nCH2] (L (CO)3, η5-C5H4CH3; M = Cr, W, Mn). The compounds are characterized both by spectroscopic means and by reaction with nucleophiles. Addition of dimethylamine results in ringopening of the carbene ligand, while 1-(diethylamino)propyne undergoes insertion into the metal-carbene bond. Reaction with methylenetrimethylphosphorane generates the conjugate base [(CO)6CrCO(CH2)2CH]-. The utility of 2-oxacycloalkylidene complexes in organic synthesis is demonstrated by functionalization of the carbene ligand into butyrolactone or 2-thiobutyrolactone upon cleavage of the metal-carbene bond by oxygen or sulfur.
- D?tz, Karl Heinz,Sturm, Werner,Alt, Helmut G.
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p. 1424 - 1427
(2008/10/08)
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- THE HYDROCYANATION OF FREE AND POLYMER-BOUND BENZOQUINONE
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The polimer-bound quinone 2 has been prepared and used in column form with organic solvents for the convenient preparation of other quinones.In contrast to the solution reaction hydrocyanation of this quinone by the Thiele-Meisenheimer reaction did not yield a useful proportion of polymer-bound dicyanohydroquinone but instead gave a mixture of products including much monocyanohydroquinone.Helferich and Bodenbender's 2,3-dicyanocyclohexan-1,4-dione is in fact wholly the di-enol and is a likely intermediate in the hydrocyanation of benzoquinone, being oxidised by the latter to 2,3-dicyanocyclohex-2-ene-1,4-dione which tautomerises to the observed product, 2,3-dicyanohydroquinone.A lower accessibility to polymer-bound reactants as compared with those in solution is implied by these results.
- Perry, Gregory J.,Sutherland, Maurice D.
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p. 1471 - 1476
(2007/10/02)
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- An Improved Synthesis of 2-Acetyl-5,8-dimethoxytetralin, an Intermediate for 4-Demethoxy-7-deoxydaunomycinone
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Vilsmeier-Haack formylation of 5,8-dimethoxy-1-tetralol yields 5,8-dimethoxy-3,4-dihydro-2-naphthaldehyde (7), which on oxidation affords the unsaturated acid (8).Hydrogenation of 8 furnishes 5,8-dimethoxytetralin-2-carboxylic acid (9) which on treatment with methyllithium gives the title compound.
- Rao, M. Vishnumurthi,Bhatt, M. Vivekananda
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p. 487 - 488
(2007/10/02)
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- PHOTOCHEMISTRY OF 5-ARYL-2(3H)-FURANONES. A NEW ROUTE TO THE SYNTHESIS OF CHROMONES
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The photochemistry of 5-phenyl-, 5-(2',5'-dimethoxyphenyl)-, 5-(2'-acetoxy-5'-methoxyphenyl)- and 5-(2',5'-diacetoxyphenyl)-2(3H)-furanone (1a-d) has been investigated.Compound 1a yields pheny vinyl ketone as expected.Similarly, 1b affords the corresponding aryl vinyl ketone but, in this case, photodimerization also occurs.Irradiation of the two o-acetoxyaryl furanones 1c and 1d gives rise to the formation of chromones as the main products.This interesting result can be accounted for in terms of a photochemical opening of the lactonic ring followed by radical addition to the acetoxy group.
- Martinez-Utrilla, R.,Miranda, M. A.
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p. 2111 - 2114
(2007/10/02)
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- 2-Aminomethyl-3,4-dihydronaphthalenes
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Compounds of the formula STR1 and pharmaceutically acceptable salts thereof, wherein X and Y are independently H, F, Cl, Br, alkyl having up to four carbons, or alkoxy having up to four carbons, but X and Y are not both H, and Z is a secondary or tertiary amino group, are useful as analgesics and tranquillizing agents for mammals.
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