479-21-0Relevant articles and documents
Three new benzophenone-xanthone dimers from the root of Garcinia dulcis
Iinuma, Munekazu,Tosa, Hideki,Ito, Tetsuro,Tanaka, Toshiyuki,Riswan, Soedarsono
, p. 1744 - 1747 (1996)
Investigation of the chemical constituents of the roots of Garcinia dulcis resulted in the isolation of three new benzophenone-xanthone dimers named garciduols A-C (1-3) in addition to a new xanthone, 1,3,6-trihydroxy- 7-methoxyxanthone (4). Five known xanthones [2,5-dihydroxy-1-methoxy-(5), 1,4,5-trihydroxy-(6), 1,3,5-trihydroxy-(7), 1,3,6-trihydroxy-5-methoxy- (8) and 1,3,6-trihydroxy-8-isoprenyl-7-methoxyxanthone (9)] were also isolated from the roots. Their structures were determined by spectroscopic analysis including two dimensional NMR. The behaviors of chemical shifts caused by acetylation and the position of the methoxyl group in the dimers characterized by model synthetic benzophenones are also discussed.
Pd-Catalyzed Enantioselective Dearomative Allylic Annulation to Access PPAPs Analogues
Li, Sanliang,Chen, Qiaoyu,Xie, Xiaoxiao,Yang, Junfeng,Zhang, Junliang
supporting information, p. 7824 - 7828 (2021/10/20)
Polycyclic polyprenylated acylphloroglucinols (PPAPs) share a common bicyclo[3.3.1]alkenone core structure and attract numerous attention from synthetic organic chemists due to their fascinating biological properties and associated synthetic challenges. We present herein that Pd-phosphoramidite catalysts promote the enantioselective dearomative allylic annulation reaction between allyl desoxyhumulones and allylic dicarbonates, affording PPAPs analogues in good yields and enantioselectivities. The reaction likely proceeds through two-step dearomative allylation by Pd, and the C-allylation pathway is the dominant mechanistic model.
Asymmetric Dearomatization/Cyclization Enables Access to Polycyclic Chemotypes
Hayashi, Mikayo,Brown, Lauren E.,Porco, John A.
, p. 4800 - 4804 (2016/10/13)
Enantioenriched, polycyclic compounds were obtained from a simple acylphloroglucinol scaffold. Highly enantioselective dearomatization was accomplished using a Trost ligand–palladium(0) complex. A computational DFT model was developed to rationalize observed enantioselectivities and revealed a key reactant-ligand hydrogen bonding interaction. Dearomatized products were used in visible light-mediated photocycloadditions and oxidative free radical cyclizations to obtain novel polycyclic chemotypes including tricyclo[4.3.1.01,4]decan-10-ones, bicyclo[3.2.1]octan-8-ones and highly substituted cycloheptanones.
Rapid synthesis of polyprenylated acylphloroglucinol analogs via dearomative conjunctive allylic annulation
Grenning, Alexander J.,Boyce, Jonathan H.,Porco, John A.
, p. 11799 - 11804 (2014/10/16)
Polyprenylated acylphloroglucinols (PPAPs) are structurally complex natural products with promising biological activities. Herein, we present a biosynthesis-inspired, diversity-oriented synthesis approach for rapid construction of PPAP analogs via double decarboxylative allylation (DcA) of acylphloroglucinol scaffolds to access allyl-desoxyhumulones followed by dearomative conjunctive allylic alkylation (DCAA).
Asymmetric, stereodivergent synthesis of (-)-clusianone utilizing a biomimetic cationic cyclization
Boyce, Jonathan H.,Porco, John A.
, p. 7832 - 7837 (2014/08/05)
We report a stereodivergent, asymmetric total synthesis of (-)-clusianone in six steps from commercial materials. We implement a challenging cationic cyclization forging a bond between two sterically encumbered quaternary carbon atoms. Mechanistic studies point to the unique ability of formic acid to mediate the cyclization forming the clusianone framework. Aim for selectivity: (-)-Clusianone was produced by a stereodivergent asymmetric total synthesis in six steps from commercial materials. The synthesis utilizes a challenging formic acid-mediated cationic cyclization forging a bond between two sterically encumbered quaternary carbon atoms.
Facile formation of methylenebis(chalcone)s through unprecedented methylenation reaction. Application to antiparasitic and natural product synthesis
Thevenin, Marion,Mouray, Elisabeth,Grellier, Philippe,Dubois, Joelle
, p. 2986 - 2992 (2014/05/20)
The formation of methylenebis(chalcone)s has been discovered during deprotection with methoxymethyl groups from trihydroxychalcones. Studies on this methylenation reaction led to a mechanism hypothesis that was extended to other chalcones and to dihydrochalcone, acetophenone, benzophenone and flavone derivatives. This new method was applied to the rapid synthesis of natural product piperanduncin C. These original methylenebis compounds were also evaluated for their antiparasitic activity. Copyright
Manganese(III)-mediated transformations of phloroglucinols: A formal oxidative [4 + 2] cycloaddition leading to bicyclo[2.2.2]octadiones
Mitasev, Branko,Porco Jr., John A.
supporting information; experimental part, p. 2285 - 2288 (2009/11/30)
Manganese(III)-mediated oxidative transformations of dearomatized phloroglucinol (1,3,5-trihydroxybenzene) derivatives are reported. A number of cyclization modes have been observed, including polycyclization to afford bicyclo[2.2.2]octadiones via a forma
