2150-46-1Relevant articles and documents
Synthesis of methyl 3,6-dioxo-endo-tricyclo[6.2.1.0 2,7]undeca-4,9-diene-2-carboxylate as synthetic intermediate for conduritol deravatives
Mamaghani,Pourali
, p. 347 - 349 (2002)
Gentisic acid reacted with methyl iodide in HMPA to give 94% of the corresponding methyl ester. Its oxidation with Ag2O in toluene afforded 57% of methoxycarbonylbenzoquinone as yellow crystals. Reaction of the latter with cyclopentadiene resulted in formation of methyl 3,6-dioxotricyclo[6.2.1.02,7]undeca-4,9-diene-2-carboxylate (21%).
STEREOCONTROLLED SYNTHESIS OF CLERODIN HOMOLOG - A SYNTHETIC APPROACH TO STRUCTURE-ACTIVITY RELATIONSHIPS -
Kojima, Yasuhiro,Kato, Natsuki
, p. 5033 - 5036 (1980)
In order to elucidate the structure-activity relationships of the antifeeding diterpenes having a neo-clerodane skeleton, clerodin homolog 5 was stereoselectively synthetized through 18 steps via a key intermediate 11.Perhydrofurofuran ring in the synthesized homolog was more unstable than that of the natural product, and gave a tri-MeOH adduct 3 in a similar behavior to that of the model compound 1 and 2.
Macrocyclic pentamers functionalised around their periphery as potential building blocks
Nam, Seong,Ware, David C.,Brothers, Penelope J.
, p. 8389 - 8393 (2019)
The elaboration of a five-fold symmetric macrocyclic aromatic pentamer bearing peripheral benzyloxy and hydroxyl groups is described. These could be used to explore further functionalisation for use as pentagonal building blocks. The internal fluorine-substituted macrocycle has been prepared via a one-pot procedure which is an improvement on the stepwise chain growth approach reported in the literature.
Studies on quinones. Part 35: Access to antiprotozoal active euryfurylquinones and hydroquinones
Valderrama, Jaime A.,Benites, Julio,Cortés, Manuel,Pessoa-Mahana, David,Prina, Eric,Fournet, Alain
, p. 881 - 886 (2002)
(+)-Euryfuran adds regiospecifically to activated monosubstituted 1,4-benzoquinones under mild conditions to give the corresponding Michael adducts which, depending on the quinone substituent, undergo in situ redox reactions to the respective euryfurylbenzoquinones. One of these Michael adducts undergoes a facile stereoselective cyclisation under oxidant conditions to afford a naphthofuro[4,3-c]benzopyran derivative. The in vitro activities of the obtained euryfurylquinones and hydroquinones against Leishmania amazonensis are described.
A Structure-Reactivity Relationship of the Tandem Asymmetric Dihydroxylation on a Biologically Relevant Diene: Influence of Remote Stereocenters on Diastereofacial Selectivity
Gill, Daniel M.,Male, Louise,Jones, Alan M.
supporting information, p. 7568 - 7577 (2019/12/11)
The Sharpless asymmetric dihydroxylation (AD) finds widespread use in natural product and drug molecule syntheses, in part, due to its efficiency and predictability. However, the tandem AD of dienes is much less studied, but important in complex molecular synthesis. Herein, a biologically relevant tandem AD is reported, and several anomalies are discovered with the accepted model. These include the formation of unpredicted diastereoisomers, with matched and mismatched stereocenters contradicting the Sharpless mnemonic device. From a structural analysis of the tandem AD, we present a strategy to improve asymmetric induction in sterically hindered alkenes using double diastereodifferentiation from a 9-bond distant stereocenter. A theoretical justification for the unpredicted stereoselectivity, accounting for the influence of steric hindrance and pre-installed chirality, is proposed.
Mechanistic Studies of the Deslongchamps Annulation
Kreibich, Michael,Petrovi?, Denis,Brückner, Reinhard
supporting information, p. 1116 - 1133 (2018/02/14)
The Cs2CO3-mediated annulations ("Deslongchamps annulations") of three spirocyclic benzoquinone monoketals 5b-d with an ester or acyl substituent at C-2 to two tert-butyl esters of λδ-unsaturated β-ketocarboxyl acids ("Nazarov reagents" 2a,b) were monitored 1H NMR spectroscopically. This revealed that a primary product, by all likelihood the Michael adduct, forms fast and prior to the appearance of the Deslongchamps adduct. These primary products form reversibly. This was proved by two crossover and four scavenging experiments. Therein, components already incorporat.