Tumor Inhibitors. X.<sup>1</sup> Photochemical Synthesis of Phenanthrenes. Synthesis of Aristolochic Acid and Related Compounds<sup>2-4</sup>

Kupchan, S. Morris; Wormser, Henry C.

doi:10.1021/jo01022a046

Cited by 85 publications

(23 citation statements)

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“…Im vorliegenden Fall entstanden die beiden Regioisomere 22 und 23 in einem Regioisomerenverhältnis r.r. Weitere einfache Phenanthren-Naturstoffe, die durch eine [6p]-Cyclisierung zugänglich wurden, sind die Plectranthone, [29] die Aristolochische Säure, [30] (AE )-Tylophorin, [31] die Phenanthrene TaIV und TaVIII [32] und das diterpenoide Chinon (AE )-Danshexinkun A. [33] Selbst am Ende einer Synthese von komplexen Phenanthrenen kann die [6p]-Cyclisierung effektiv als Schlüsselreaktion eingesetzt werden.…”

Section: Aufsätzeunclassified

“…Die Herstellung von Aporphin-Alkaloiden über eine [6p]-Photocyclisierung zählt zu den am längsten bekannten und bestuntersuchten Routen dieses Typs. [36] Beispielhaft erwähnt sei die von Cava et al gewählte Route zur Synthese des (AE )-Dicentrins (30). [37] Durch Bischler-Napieralski-Reaktion wurde aus dem Amid [37] (AE )-Aporphin, [38] (AE )-Nuciferin, [38,39] (AE )-Glaucin, [39] (AE )-Cassamedin, [40] (AE )-Sinomendin, [41] (AE )-Elmerrillicin, [42] Pontevedrin, [43] Cepharadion B [44] und (AE )-Goudotianin.…”

Section: Aufsätzeunclassified

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Photochemische Reaktionen als Schlüsselschritte in der Naturstoffsynthese

2011

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Photochemische Reaktionen bereichern in signifikanter Weise das Repertoire zur Knüpfung von Kohlenstoff‐Kohlenstoff‐Bindungen und machen ungewöhnliche, auf herkömmlichem Weg nicht erhältliche Molekülgerüste zugänglich. In diesem Aufsatz werden die wichtigsten Umsetzungen der Photochemie vorgestellt, die auf breiter Front Einzug in die Naturstoffsynthese gehalten haben. Beispielhaft werden einzelne Totalsynthesen diskutiert, wobei besonderes Augenmerk auf den photochemischen Schlüsselschritt sowie dessen Stereoselektivität gerichtet ist. Dabei wird das photochemisch erzeugte Molekül in Relation zur Struktur des Naturstoffs gebracht, und Folgereaktionen werden, wo notwendig, illustriert und klassifiziert.

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Section: Aufsätzeunclassified

Photochemische Reaktionen als Schlüsselschritte in der Naturstoffsynthese

2011

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“…31 Both methods are similar and rely on a photochemical coupling step that is impracticable for larger-scale development. In addition, too many steps are involved, yields at some stages are low (in particular, the final basic hydrolysis of AA I methyl ester gives AA I in only 6% yield 30 ), and the route lacks versatility and would not be easily adaptable to the synthesis of the 7-bromoaristolactams 13 and 14 that we saw as the critical intermediates in our synthetic approach to the DNA adducts 3 – 6 . The work of Castedo and his associates, 32 which uses an internal benzyne reaction to construct the aristolactam framework, did not seem applicable to the synthesis of the AAs themselves.…”

Section: Resultsmentioning

confidence: 99%

Total Synthesis of the Aristolochic Acids, Their Major Metabolites, and Related Compounds

Attaluri

Iden

Bonala

et al. 2014

Chem. Res. Toxicol.

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Plants from the Aristolochia genus have been recommended for the treatment of a variety of human ailments since the time of Hippocrates. However, many species produce the highly toxic aristolochic acids (AAs), which are both nephrotoxic and carcinogenic. For the purposes of extensive biological studies, a versatile approach to the synthesis of the AAs and their major metabolites was devised based primarily on a Suzuki–Miyaura coupling reaction. The key to success lies in the preparation of a common ring-A precursor, namely, the tetrahydropyranyl ether of 2-nitromethyl-3-iodo-4,5-methylendioxybenzyl alcohol (27), which was generated in excellent yield by oxidation of the aldoxime precursor 26. Suzuki–Miyaura coupling of 27 with a variety of benzaldehyde 2-boronates was accompanied by an aldol condensation/elimination reaction to give the desired phenanthrene intermediate directly. Deprotection of the benzyl alcohol followed by two sequential oxidation steps gave the desired phenanthrene nitrocarboxylic acids. This approach was used to synthesize AAs I–IV and several other related compounds, including AA I and AA II bearing an aminopropyloxy group at position-6, which were required for further conversion to fluorescent biological probes. Further successful application of the Suzuki–Miyaura coupling reaction to the synthesis of the N-hydroxyaristolactams of AA I and AA II then allowed the synthesis of the putative, but until now elusive, N-acetoxy- and N-sulfonyloxy-aristolactam metabolites.

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“…36 64–65 °C); 1 H NMR (500 MHz, CDCl 3 ) δ 8.15 (dd, J = 7.7, 1.4 Hz, 1H), 7.62 (td, J = 7.5, 1.4 Hz, 1H), 7.56 (td, J = 7.6, 1.3 Hz, 1H), 7.4 (dd, J = 7.6, 1.0 Hz, 1H), 5.86 (s, 2H), 3.91 (s, 3H); 13 C NMR (125 MHz, CDCl 3 ) δ 166.8, 133.3, 133.2, 131.8, 130.8, 130.4, 130.2, 77.7, 52.6; IR (film) 3024, 2960, 1714, 1569, 1429, 1377, 1285, 1086 cm −1 ; HRMS (CI) calcd for C 9 H 9 O 2 [M-NO 2 ] + , m/z = 149.0602; found 149.0597.…”

Section: Methodsmentioning

confidence: 99%

Minimizing the Amount of Nitromethane in Palladium-Catalyzed Cross-Coupling with Aryl Halides

Walvoord

Kozlowski

2013

J. Org. Chem.

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A method for the formation of arylnitromethanes is described that employs readily available aryl halides or triflates and small amounts of nitromethane in a dioxane solvent, thereby reducing the hazards associated with this reagent. Specifically, 2–10 equivalents (1–5% v/v) of nitromethane can be employed in comparison to prior work that used nitromethane as solvent (185 equivalents). The present transformation provides high yields at relatively low temperatures and tolerates an array of functionality, including heterocycles and substantial steric encumbrance.

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Tumor Inhibitors. X.¹ Photochemical Synthesis of Phenanthrenes. Synthesis of Aristolochic Acid and Related Compounds^2-4

Cited by 85 publications

References 1 publication

Photochemische Reaktionen als Schlüsselschritte in der Naturstoffsynthese

Photochemische Reaktionen als Schlüsselschritte in der Naturstoffsynthese

Total Synthesis of the Aristolochic Acids, Their Major Metabolites, and Related Compounds

Minimizing the Amount of Nitromethane in Palladium-Catalyzed Cross-Coupling with Aryl Halides

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Tumor Inhibitors. X.1 Photochemical Synthesis of Phenanthrenes. Synthesis of Aristolochic Acid and Related Compounds2-4

Cited by 85 publications

References 1 publication

Photochemische Reaktionen als Schlüsselschritte in der Naturstoffsynthese

Photochemische Reaktionen als Schlüsselschritte in der Naturstoffsynthese

Total Synthesis of the Aristolochic Acids, Their Major Metabolites, and Related Compounds

Minimizing the Amount of Nitromethane in Palladium-Catalyzed Cross-Coupling with Aryl Halides

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Product

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Tumor Inhibitors. X.¹ Photochemical Synthesis of Phenanthrenes. Synthesis of Aristolochic Acid and Related Compounds^2-4