1083-11-0Relevant articles and documents
A Radical-Based Synthesis of Lingzhiol
Mehl, Lea-Marina,Maier, Martin E.
, p. 9844 - 9850 (2017/09/23)
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).
Rapid probing of the reactivity of P450 monooxygenases from the CYP116B subfamily using a substrate-based method
Li, Ren-Jie,Xu, Jian-He,Yin, Yue-Cai,Wirth, Nicolas,Ren, Jiang-Meng,Zeng, Bu-Bing,Yu, Hui-Lei
supporting information, p. 8928 - 8934 (2016/10/13)
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.
Design and synthesis of 4-aryl-4-oxobutanoic acid amides as calpain inhibitors
Zhang, Yong,Jung, Seo Yoon,Jin, Changbae,Kim, Nam Doo,Gong, Ping,Lee, Yong Sup
scheme or table, p. 502 - 507 (2011/02/28)
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.
Synthesis of Methoxy-2-hydroxy-1,4-naphthoquinones and Reaction of One Isomer with Aldehydes under Basic Conditions
Ameer, Farouk,Giles, Robin G. F.,Green, Ivan R.,Pearce, Rene
, p. 1247 - 1258 (2007/10/03)
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.
Direct synthesis of γ-butyrolactones via γ-phenyl substituted butyric acids mediated benzyl radical cyclization
Mahmoodi,Jazayri
, p. 1467 - 1475 (2007/10/03)
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.
Formal total synthesis of (+)-diepoxin σ
Wipf, Peter,Jung, Jae-Kyu
, p. 6319 - 6337 (2007/10/03)
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.
Asymmetric synthesis and antitumor activity of cycloalkanin
Wu, Xihan,Xu, Liang,Cai, Junchao
, p. 2635 - 2638 (2007/10/03)
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.
Anodic Oxidation as a Synthetic Expedient to Naphthoquinone and Anthraquinone Ketals
Yang, Zhen,Cui, Yu Xin,Wong, Henry N. C.,Wang, Ru Ji,Mak, Thomas C. W.,et al.
, p. 3293 - 3302 (2007/10/02)
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.
Facile Interconversion of the Isomeric Acid Chlorides Derived from Half Methyl Esters of 3-Methoxyphthalic Acid
Gupta, Dahmendra N.,Hodge, Philip,Hurley, Peter N.
, p. 391 - 394 (2007/10/02)
The isomeric acid chlorides obtained by treating the half methyl esters of 3-methoxyphthalic acid with thionyl chloride interconvert so readily that it is not practical to isolate one acid chloride free of the other.At equilibrium the main isomer is the a
Steric and Inductive Effects on the Hydrolysis of Quinone Bisketals
Chen, Chung-Pin,Swenton, John S.
, p. 4569 - 4576 (2007/10/02)
The effects of allylic substituents on the regiochemistry of monohydrolysis of tetralin-type quinone bisketals 12 have been studied.The requisite bisketals were prepared by anodic oxidation of the corresponding 1-substituted 5,8-dimethoxytetralin.Product studies establish that hydroxyl and ether functions at the allylic position preferentially afford quinone monoketals of type 13 wherein the ketal function nearest to the allylic substituent is hydrolyzed.The fluoro system also preferentially forms the monoketal 13 (R = F).A series of alkyl substituents were also studied, and increasing the size of the group led to increasing regioselectivity in favor of 13.Only the Δ1,2-unsaturated systems 12j,k preferentially gave monoketals in which the more distant ketal function had hydrolyzed.Kinetic studies established at least two major factors in the regiochemistry of the bisketal hydrolysis.While both the oxygenated and alkylated substituents gave monoketals 13 in which hydrolysis had selectively occurred at the nearer ketal function, the origins of the observed regioselectivity are different.Oxygenated systems gave the observed regiochemistry due to a rate retardation of the hydrolysis of the more distant ketal by what is proposed to be an inductive effect.However, alkyl substituents exerted their effect by increasing the rate of hydrolysis of the nearer ketal function due to a relief of strain energy.
