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A biosynthesis of the structurally complex nonadride CP-225,917 (1) is outlined. A key step in this proposal is the dimerization of a C(16) anhydride derived from the condensation of lauric acid and oxaloacetic acid. An important element of this step is a templating effect imposed by two thioester linkages, reminiscent of a polyketide or fatty acid synthase pathway. On the basis of this principle, the dimerization of two C(11) anhydrides, templated by a 1,n-diol tether, leading to the core structure of CP-225,917 and CP-263,114 was investigated. 相似文献
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[reaction: see text] Assembly of the carbocyclic core of CP-263,114 has been accomplished efficiently and in high yield. Key steps include a phenolic oxidation/intramolecular Diels-Alder sequence, tandem radical cyclization, and the late-stage fragmentation of a densely functionalized isotwistane skeleton. 相似文献
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《Nachrichten aus der Chemie》1999,47(12):1423-1427
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Alan Armstrong Nicholas G.M. DaviesNathaniel G. Martin Alistair P. Rutherford 《Tetrahedron letters》2003,44(20):3915-3918
Asymmetric synthesis of a functionalised cyclohexenone required for total synthesis of CP-225,917 and CP-263,114 is reported, using a Lewis acid-promoted Diels-Alder reaction between a 2-silyloxy-1,3-diene and a dienophile bearing an oxazolidinone auxiliary. A novel method for appendage of the exocyclic malonate unit, via cyclopropane ring opening, is also described. 相似文献
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Matsushita T Ashida H Kimachi T Takemoto Y 《Chemical communications (Cambridge, England)》2002,(8):814-815
Assembly of the highly functionalized carbocyclic core of CP-263,114 has been accomplished by using radical-mediated fragmentation with lithium naphthalenide as a key step. 相似文献
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[reaction: see text]. Feeding experiments using a deuterium labeled C16 maleic anhydride and whole cell culture of ATCC 74256 led to the isolation of phomoidride B with deuterium incorporation at C(7) and C(19) as determined by 2H NMR and electrospray mass spectrometry. This result is in accord with a decarboxylative homodimerization of the C16 maleic anhydride as a key biosynthetic step leading to phomoidride B. 相似文献
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Nicolaou KC Zhong YL Baran PS Jung J Choi HS Yoon WH 《Journal of the American Chemical Society》2002,124(10):2202-2211
The completion of the total syntheses of the CP-molecules is reported. Several strategies and tactics, including the use of amide-based protecting groups for the homologated C-29 carboxylic acid and the use of an internal pyran protecting group scheme, are discussed. The endeavors leading to the design of new methods for the homologation of hindered aldehydes and to the isolation of a polycyclic byproduct (23), which inspired the development of a new series of reactions based on iodine(V) reagents, are described. In addition, the discovery and development of the LiOH-mediated conversion of CP-263,114 (1) to CP-225,917 (2) is described, and a mechanistic rationale is presented. Finally, a synthetic route to complex analogues of the CP-molecules harboring a maleimide moiety in place of the maleic anhydride is presented. 相似文献
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《Tetrahedron: Asymmetry》1999,10(20):3963-3968
Two synthetic methods of CP-060S, (−)-2-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-[3-[N-methyl-N-[2-[3,4-(methylenedioxy)phenoxy]ethyl]amino]propyl]-1,3-thiazolidin-4-one (−)-1, have been developed. The first method involved preparative HPLC resolution of bromo-intermediate 4. The second one involved resolution of 1 by crystallization of the corresponding diastereomeric salt. 相似文献
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An efficient route detailing the construction of the central core of pierisformaside C, the first grayanane-type diterpene to possess three central double bonds, is reported. 相似文献
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Ohmori N 《Chemical communications (Cambridge, England)》2001,(17):1552-1553
The highly functionalized core structure of phomoidride B (CP-263,114) was pursued by using intermolecular oxidopyrylium-alkene cyclization as one of the key steps. 相似文献
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The synthesis of 2-methyl-3-(2-propenyl)pyrrole () and E- and Z-2-methyl-3-(1-propenyl)pyrroles () via the reaction of 3-butenyl methyl ketoxime () with acetylene in the KOH-DMSO system is reported. 相似文献
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Nicolaou KC Baran PS Zhong YL Fong KC Choi HS 《Journal of the American Chemical Society》2002,124(10):2190-2201
Crucial model synthetic and mechanistic studies directed toward the development of methodology for the construction of the maleic anhydride moiety of the CP-molecules are described. Studies directed toward the stereoselective attachment of the upper side chain, culminating in the discovery of long-range stereochemical control, are also discussed. In addition, a first-generation strategy toward the CP-molecules, establishing key intermediate 5 as a "beachhead" from which all future operations would diverge, is also presented. Although this first-generation strategy failed to yield the target molecules, the endeavor laid the important groundwork for the next-generation drives toward the CP-molecules. 相似文献