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Nicolaou KC Chen DY Li Y Uesaka N Petrovic G Koftis TV Bernal F Frederick MO Govindasamy M Ling T Pihko PM Tang W Vyskocil S 《Journal of the American Chemical Society》2006,128(7):2258-2267
The key building blocks (6, 7, and 8) for the intended construction of the originally proposed structures of azaspiracid-1, a potent marine-derived neurotoxin, were coupled and the products elaborated to the targeted compounds (1a,b) and their C-20 epimers (2 and 3). The assembly of the three intermediates was accomplished by a dithiane-based coupling reaction that united the C(1)-C(20) (7) and C(21)-C(27) (8) fragments, followed by a Stille-type coupling which allowed the incorporation of the C(28)-C(40) fragment (6) into the growing substrate. Neither of the final products (1a,b) matched the natural substance by TLC or (1)H NMR spectroscopic analysis, suggesting one or more errors in the originally proposed structure for this notorious biotoxin. 相似文献
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Total synthesis and chemical biology of the sarcodictyins. 总被引:1,自引:0,他引:1
K C Nicolaou J Pfefferkorn J Xu N Winssinger T Ohshima S Kim S Hosokawa D Vourloumis F van Delft T Li 《Chemical & pharmaceutical bulletin》1999,47(9):1199-1213
The sarcodictyins A-F and eleutherobin comprise a family of marine-derived diterpenoids with potent cytotoxicities against various tumor cell lines. Investigations have revealed that several of these compounds exert their cytotoxic effects through tubulin binding in a mechanism analogous to that of the clinical anticancer drug Taxol. The biological importance, challenging molecular architecture, and relative scarcity of these natural products have prompted several groups to undertake their total chemical synthesis. In this review, we summarize the current synthetic efforts and examine the preliminary structure-activity relationships which have emerged from early combinatorial libraries. 相似文献
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Nicolaou KC Montagnon T Vassilikogiannakis G Mathison CJ 《Journal of the American Chemical Society》2005,127(24):8872-8888
Members of the coleophomone family of natural products all possess several intriguing and challenging architectural features, as well as exhibit unusual biological activity. They, therefore, constitute attractive targets for synthesis. In this Article, we describe the total synthesis of coleophomones B (2), C (3), and D (4). The highly strained and congested 11-membered macrocycle of coleophomones B (2) and C (3) was constructed using an impressive olefin metathesis reaction. Furthermore, both of the requisite geometric isomers of the Delta(16,17) within the macrocycle could be accessed from a common precursor, facilitating a divergence that lent the coleophomone B (2)/C (3) synthesis an unusually high degree of efficiency. The synthesis of coleophomone D (4) confirmed that it exists as a dynamic mixture of isomeric forms with a different aromatic substitution pattern from the other family members. 相似文献
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