Total syntheses of (.+-.)-cephalotaxine and (.+-.)-8-oxocephalotaxine

Kuehne, Martin E.; Bornmann, William G.; Parsons, William H.; Spitzer, Timothy D.; Blount, John F.; Zubieta, J.

doi:10.1021/jo00250a008

Cited by 72 publications

(41 citation statements)

References 2 publications

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“…No double-bond isomers were detected; furthermore, there is no loss of stereointegrity. The transformation of 41 into cephalotaxine (3) by bishydroxylation of the cyclopentene moiety using OsO 4 , oxidation of the diol to the diketone, formation of the methyl enol ether, and diasteroselective reduction of the remaining keto group was performed according to a known procedure [30,33].…”

Section: Cephalotaxinementioning

confidence: 99%

Synthesis of natural products and analogs using multiple Pd-catalyzed transformations

Tietze

Kinzel

2007

Pure and Applied Chemistry

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Palladium-catalyzed transformations are of great importance in modern synthetic organic chemistry. The vast number of reactions that can be catalyzed by Pd 0 -as well as Pd 2+ -complexes in combination with the relative stability of the intermediates offers the intriguing opportunity of carrying out multiple consecutive bond-forming processes. They can be even performed in a domino fashion and in the presence of chiral ligands to allow the efficient preparation of almost enantiopure compounds. In this article, the use of double Heck, Tsuji-Trost-Heck, and Wacker-Heck reactions for the total syntheses of estradiol, spinosyn A analogs, cephalotaxine, and vitamin E is described.

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Section: Cephalotaxinementioning

confidence: 99%

Synthesis of natural products and analogs using multiple Pd-catalyzed transformations

Tietze

Kinzel

2007

Pure and Applied Chemistry

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“…Several elegant syntheses of 1 have been reported over the past three decades. The racemic approaches have embodied several key transformations, including Nazarov cyclization, [19] photo-stimulated S RN 1 cyclization, [20] Claisen rearrangement, [21,22] oxidative ring contraction, [23] acylnitroso Diels-Alder cycloaddition, [24,25] transannular N-conjugate addition, [26,27] intramolecular alkyne hydroamination, [28] and reductive ring expansion of tetrahydrosioquinoline intermediates. [29,30] Non-racemic routes have featured electrophilic aromatic substitution, [31] Heck arylation, [32,33] Pummerer-electrophilic aromatic substitution cascade, [34][35][36] and acid catalyzed ring expansion of cyclobutanol derivatives.…”

mentioning

confidence: 99%

Synthesis of Antiproliferative Cephalotaxus Esters and Their Evaluation against Several Human Hematopoietic and Solid Tumor Cell Lines: Uncovering Differential Susceptibilities to Multidrug Resistance

Eckelbarger

Wilmot

Epperson

et al. 2008

Chemistry A European J

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Deoxyharringtonine (2), homoharringtonine (3), homodeoxyharringtonine (4), and anhydroharringtonine (5) are reported to be among the most potent members of the antileukemia alkaloids isolated from the Cephalotaxus genus. Convergent syntheses of these four natural products are described, each involving novel synthetic methods and strategies. These syntheses enabled evaluation of several advanced natural and non-natural compounds against an array of human hematopoietic and solid tumor cells. Potent cytotoxicity was observed in several cell lines previously not challenged with these alkaloids. Variations in the structure of the ester chain within this family of alkaloids confer differing activity profiles against vincristine-resistant HL-60/RV+, signalling new avenues for molecular design of these natural products to combat multi-drug resistance.

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“…This presumably resulted from the steric hindrance surrounding C-12, providing an environment similar to that of a neopentyl system. On the other hand, with LAH reduction, 1, again, was too labile, whereas 11 did proceed sluggishly under reflux [14], and instead of the expected triol, a recyclized tetrahydrofuranol 8 [6] was obtained only in a low yield.…”

Section: Derivatizations Of the Scalaranesmentioning

confidence: 94%

“…This opened an opportunity to us to employ 1 as the primary starting material for the chemical derivatizations of the scalarane derivatives (Scheme 1). The scalaranes obtained here included 12-oxoheteronemin (7); 12-deacetyl-12-epi-20-deoxoscalarin (8); scalarafuran (9); 16-deacetoxy-15,16-dehydroscalarafuran (10); 12-deacetyl-12-episcalaradial (11); 12-deacetyl-12,18-diepiscalaradial (12); 12-deacetyl-12-oxoscalaradial (13); and 12-episcalaradial (14). Please note here that, in order to facilitate the discussion regarding the SARs, the order of the compound entries mentioned above was referred to the structural similarity as tabulated in Table 1.…”

Section: Derivatizations Of the Scalaranesmentioning

confidence: 99%

Structure-activity relationships of antitubercular scalaranes: Heteronemin revisited

Jaisamut

Thengyai

Yuenyongsawad

et al. 2009

Pure and Applied Chemistry

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A series of heteronemin-related antitubercular scalaranes, both from natural products and from chemical derivatization, were subjected to structure-activity investigations. Based on the activity profile, three main regions; i.e., the substituted groups hovering over C-19/C-18 and furan moiety, the functionalities in the vicinity of C-16 and the right-hand side of ring D, and the substituted groups on C-12, were speculated as the areas influencing the antitubercular activity of the scalaranes. The results suggested the promising possibility for the further investigation toward the modes of actions and/or target sites of the compounds.

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Total syntheses of (.+-.)-cephalotaxine and (.+-.)-8-oxocephalotaxine

Cited by 72 publications

References 2 publications

Synthesis of natural products and analogs using multiple Pd-catalyzed transformations

Synthesis of natural products and analogs using multiple Pd-catalyzed transformations

Synthesis of Antiproliferative Cephalotaxus Esters and Their Evaluation against Several Human Hematopoietic and Solid Tumor Cell Lines: Uncovering Differential Susceptibilities to Multidrug Resistance

Structure-activity relationships of antitubercular scalaranes: Heteronemin revisited

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