Intramolecular Double Michael Reaction Research Articles

Asymmetric Total Synthesis of (−)-Scabronine G via Intramolecular Double Michael Reaction and Prins Cyclization

The enantioselective total synthesis of (-)-scabronine G is described. The key features of the present synthesis include the construction of a 5-6 ring system containing two quaternary carbon centers via a diastereoselective intramolecular double Michael reaction and the formation of a seven-membered ring using a Prins cyclization.

Stereoselective construction of carbocycles and heterocycles via cascade reactions involving curcumins and nitroalkenes

The reaction of curcumins with nitroalkenes has been investigated for the first time. Highly functionalized cyclohexanones possessing three contiguous chiral centers with complete diastereoselectivity have been synthesized through an inter–intramolecular double Michael reaction involving curcumin and nitroalkene under extremely simple experimental conditions (K2CO3 in aqueous THF). Under identical conditions, curcumins react with α-bromonitroalkenes to afford dihydrofurans through an intermolecular Michael addition-intramolecular nucleophilic substitution (O-alkylation), which is analogous to an ‘interrupted’ Feist–Benary reaction. These novel transformations of curcumins empower us to expand the repertoire of curcumin based therapeutics.

ChemInform Abstract: Enantioselective Synthesis of 6-Oxygenated Atisine Derivative via Intramolecular Double Michael Reaction.

Abstract An enantioselective synthesis of a 6-oxygenated atisine derivative 20 is described. The atisine skeleton 18 was stereoselectively constructed by the intramolecular double Michael reaction of the enone ester 16, derived, through the aldehyde 3, from the symmetrical ketone 4.

Syntheses of Biologically Active Natural Products and Leading Compounds for New Pharmaceuticals Employing Effective Construction of a Polycyclic Skeleton

Cascade reactions are useful methods for the construction of polycyclic skeletons, which are important cores for biological activities. A variety of cascade reactions carried out under multiple reaction conditions, such as pericyclic, polar, radical, and transition metal-catalyzed reaction conditions, have been investigated. Culmorin, pentalenene, pentalenic acid, deoxypentalenic acid, longiborneol, cedrandiol, 8,14-cedranoxide, atisirene, atisine, and estrane-type steroids were synthesized via the intramolecular double Michael reaction. Aza double Michael reaction was applied to the syntheses of tylophorine, epilupinine, tacamonine, and paroxetine. Furthermore, sequential Michael and aldol reactions were performed in both intramolecular and intermolecular manners, leading to the formation of polycyclic compounds fused to a four-membered ring. Synthesis of paesslerin A utilizing a multicomponent cascade reaction revealed an error in the proposed structure. Unique cascade reactions carried out under radical and transition metal-catalyzed reaction conditions were also investigated. With the combination of several cascade reactions, serofendic acids and methyl 7beta-hydroxykaurenoate, both of which have neuroprotective activity, were synthesized in a selective manner.

Short Synthesis of (±)-Tacamonine by the Intramolecular Double Michael Reaction

Short Synthesis of (±)-Tacamonine by the Intramolecular Double Michael Reaction

Facile Construction of the Tricyclo[5.2.1.01,5]decane Ring System by Intramolecular Double Michael Reaction: Highly Stereocontrolled Total Synthesis of (±)-8,14-Cedranediol and (±)-8,14-Cedranoxide

It was observed that the synthesis of tricyclo[5.2.1.01,5]decane 10 can be performed effectively by the intramolecular double Michael reaction of 5-(5-methoxycarbonyl-4-pentenyl)-2-cyclopenten-1-one (9). Highly stereocontrolled total syntheses of (±)-8,14-cedranediol (2) and (±)-8,14-cedranoxide (1) were accomplished by the application of this methodology. Heating 5-(1,5-dimethyl-5-ethoxycarbonylpent-4-enyl)-2-cyclopenten-1-one (15) with TMSCl, Et3N, and ZnCl2 in o-dichlorobenzene at 150 °C provided (±)-(1R*,2R*,5R*,6R*,7S*)-2,6-dimethyl-6-ethoxycarbonyltricyclo[5.2.1.01,5]-decan-9-one (16) as a single isomer. The product 16 was stereoselectively converted into the above cedranoids 2 and 1 through ring expansion chemistry.

Stereoselective synthesis of (±)-cedranediol via intramolecular double michael reaction

Total synthesis of (±)-cedranediol ( 7) was achieved using intramolecular double Michael reaction. Heating the enone 10 together with ZnCl 2, Et 3N, and TMSCl gave the tricyclo[5.2.1.0 1,5]decane 9 as a single diastereomer, which was converted into (±)-cedranediol ( 7).

ChemInform Abstract: Synthesis of Benzo(a)quinolizines by the Intramolecular Double Michael Reaction under Three Different Conditions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Stereoselective Construction of Copaborneol and Longiborneol Frameworks by Intramolecular Double Michael Reaction.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of Benzo[a]quinolizines by the Intramolecular Double Michael Reaction under Three Different Conditions

Synthesis of Benzo[a]quinolizines by the Intramolecular Double Michael Reaction under Three Different Conditions

ChemInform Abstract: Stereocontrolled Synthesis of Indolo(2,3‐a)quinolizines by Intramolecular Double Michael Reaction: Proof for Stepwise Mechanism.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Stereoselective Construction of Copaborneol and Longiborneol Frameworks by Intramolecular Double Michael Reaction.

Stereoselective syntheses of tricyclo[5.3.0.0(3,8)]decane 22 and tricyclo[6.3.0.0(3,9)]undecane 26, the basic skeletons of copaborneol and longiborneol, were achieved by the intramolecular double Michael reactions of 2-cyclopenten-1-ones 15-17. The substrates were prepared starting with tricyclo[5.2.1.0(2,6)]deca-4,8-dien-3-one (6). The intramolecular double Michael reactions were carried out under three different conditions: TMSCl-Et(3)N-ZnCl(2), TMSI-(TMS)(2)NH, and Bu(2)BOTf-(TMS)(2)NH. The framework 26 of longiborneol was constructed in good yields using the latter two reagent systems.

Developments of highly stereoselective domino reactions and application to medicinal chemistry

Simple and highly effective methods for the synthesis of polycyclic ring systems via two types of intramolecular domino reactions are developed and presented. The first example is an intramolecular double Michael reaction, whose scope-limitation, mechanism and application to natural product synthesis are discussed. The intramolecular Michael-aldol reaction is the second case, which provides a nice method for the preparation of polycyclic compounds having a four-membered ring system. In addition, some related reactions of these methods are described.

Stereocontrolled synthesis of indolo[2,3-a]quinolizines by intramolecular double Michael reaction: proof for stepwise mechanism

Indolo[2,3-a]quinolizines 3 were stereoselectively synthesized by the intramolecular double Michael reaction of amide esters 2, the indole nitrogen of which was protected with a tosyl group, using ButMe2SiOSO2CF3 in the presence of Et3N.

Effective Ring Formations and Natural Product Syntheses

Simple and effective synthetic methods of polycylic ring systems in intramolecular reactions are presented. The first example is Diels-Alder reaction, which has been applied to total synthesis of steroids and terpenes. The intramolecular double Michael reaction is the second case, whose mechanism and application to natural product synthesis are also discussed. In addition, some related reactions of the latter are described.

Syntheses of Polycyclic Natural Products Employing the Intramolecular Double Michael Reaction

AbstractThe one‐pot intramolecular double Michael reaction of compounds having two different α, β‐unsaturated carbonyl groups to form polycyclic compounds can be carried out by three different methods: in the first the substrate is treated with lithium hexamethyldisilazide, in the second with chlorotrimethylsilane, triethylamine, and zinc chloride at an elevated temperature, and in the third with tert‐butyldimethylsilyl trifluoromethanesulfonate and triethylamine. The reaction proceeds with complete regioselectivity and high stereoselectivity following a stepwise mechanism. Spiro‐fused bicyclo[2.2.2]octane derivatives can be constructed with high stereoselectivity by the intromolecular double Michael reaction by using the first method. Enantiomerically pure atisine and the enantiomer of atisirene were synthesized stereoselectively by application of this methodology. The syntheses of steroids and angular triquinane‐type sesquiterpenoids were possible with the second method. Heterocyclic compounds with a bridgehead nitrogen atom were obtained by the reaction of α, β‐unsaturated amides following the second and third methods. The asymmetric synthesis of tylophorine with diastereofacial control was achieved by the intramolecular reaction according to the third method. The sulfur‐mediated intramolecular double Michael reaction utilizing the third method produced trans‐hydroindane derivatives. Furthermore, the intramolecular Michael‐aldol reaction can be employed in synthesizing polycyclic systems with cyclobutane units by treatment with tert‐butyldimethylsilyl trifluoromethanesulfonate in the presence of triethylamine. The intermolecular double Michael reaction and related reactions will also be described.

Enantioselective synthesis of 6-oxygenated atisine derivative via intramolecular double Michael reaction

An enantioselective synthesis of a 6-oxygenated atisine derivative 20 is described. The atisine skeleton 18 was stereoselectively constructed by the intramolecular double Michael reaction of the enone ester 16, derived, through the aldehyde 3, from the symmetrical ketone 4.

ChemInform Abstract: Asymmetric Total Synthesis of Naturally Occurring (R)‐(‐)‐Enantiomer of Tylophorine via Intramolecular Double Michael Reaction.

The first asymmetric total synthesis of the naturally occurring (R)-(–)-enantiomer (1) of tylophorine was achieved with high enantioselectivity via the intramolecular double Michael reaction of α,β-unsaturated esters (10) and (20), having two different chiral auxiliaries, with t-butyldimethylsilyl trifluoromethanesulphonate in the presence of triethylamine. (–)-Phenylmenthol and (2R,4S,5R)-(–)-4-(t-butyldimethylsiloxymethyl)-5-hydroxy-2-phenyl-1,3-dioxane, readily available from D-glucose, were used as chiral auxiliaries.

ChemInform Abstract: Asymmetric Total Synthesis of Atisine via Intramolecular Double Michael Reaction.

The bridged, pentacyclic intermediate 2 for atisine (1) was synthesized in a naturally occurring enantiomeric form from dimethyl cyclohexanone-2,6-dicarboxylate (6). The synthesis is composed of the following key steps: (1) formation of the azabicyclo [3.3.1] nonane by a double Mannich reaction, (2) enantioselective conversion by a lipase-catalyzed acylation, (3) stereoselective hydroboration in the presence of BF 3 .Et 2 O, and (4) construction of the bicyclo [2.2.2] octane ring system by an intramolecular double Michael reaction

Asymmetric total synthesis of atisine via intramolecular double Michael reaction

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAsymmetric total synthesis of atisine via intramolecular double Michael reactionMasataka Ihara, Makoto Suzuki, Keiichiro Fukumoto, and Chizuko KabutoCite this: J. Am. Chem. Soc. 1990, 112, 3, 1164–1171Publication Date (Print):January 1, 1990Publication History Published online1 May 2002Published inissue 1 January 1990https://doi.org/10.1021/ja00159a042RIGHTS & PERMISSIONSArticle Views1393Altmetric-Citations76LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts