Total Synthesis of taxol. 2. Construction of A and C ring intermediates and initial attempts to construct the ABC ring system
摘要:
A method for the formation of Taxol's ABC ring system has been developed. General methods for the synthesis of versatile synthons for Taxol's A ring (8) and C ring (55) are presented. A model study using a simplified C ring synthon (17) confirmed the viability of the sequential Shapiro-McMurry strategy for formation of Taxol's B ring. Careful exploration of the chemistry of various A-B ring conjugates allowed the development of a successful method for formation of the B ring in a more functionalized system.
A convergent strategy towards taxol. A facile enantioselective entry into a fully functionalized ring A system
作者:K. C. Nicolaou、C.-K. Hwang、E. J. Soresen、C. F. Clairborne
DOI:10.1039/c39920001117
日期:——
Key intermediates 10–12 related to the taxol ring A system have been synthesized in enantiomerically pure form by a short and efficient route featuring a Diels–Alder reaction and a Corey oxazaborolidine reduction.
通过以 Diels-Alder 反应和 Corey oxazaborolidine 还原为特征的简短高效路线,合成了对映体纯度为 10-12 的与紫杉醇环 A 系统相关的关键中间体。
Intramolecular Diels−Alder Reactions Using α-Methylene Lactones as Dienophile
作者:Frank Richter、Matthias Bauer、Caroline Perez、Cäcilia Maichle-Mössmer、Martin E. Maier
DOI:10.1021/jo016116a
日期:2002.4.1
were prepared and reacted in the presence of zinc metal with ethyl 2-bromomethylacrylate to provide in a Reformatsky-like reaction alpha-methylene lactones carrying a dienyl side chain. Thermolysis of these compounds (11, 21, 29, and 37) gave in an intramolecularDiels-Alderreaction the corresponding tricyclic cycloadducts (51, 52, 53, and 54). The cycloadditions took place with good diastereoselectivity
The unexpected formation of bicyclo[2.2.1]heptane derivatives by Lewis acid-catalyzed transannular double cyclization
作者:Vattoly J. Majo、Shuichi Suzuki、Masahiro Toyota、Masataka Ihara
DOI:10.1039/b005727o
日期:——
unexpectedly led to the formation of bicyclo[2.2.1]heptanederivatives 18 and 19a. Since the formation of spiro compounds by allylsilane terminated domino reaction has no precedent in literature, we extended the reaction conditions to unactivated olefins. Spontaneous aromatization accompanied by bicyclic ring formation was observed in these cases. Bicyclo[2.2.1]heptanederivative 11 was also formed in
A tandem radical macrocyclisation - radical transannulation strategy to the taxane ring system
作者:Stephen A. Hitchcock、Gerald Pattenden
DOI:10.1016/s0040-4039(00)61300-x
日期:1992.8
Treatment of the iodo-trienone (8 b) with tri-n-butyltin hydride in the presence of AIBN is shown to produce the taxane ring system (11) by way of a tandem radical macrocyclisation - radical transannulation sequence, i.e. (8 b) → (9) → (11) (cf. Scheme 1).
Influence of Alkyl Substituent on the Asynchronous Transition Structure of Boron-Catalyzed Diels-Alder Cycloaddition of .alpha.,.beta.-Unsaturated Aldehydes with 1,1-Dimethyl-1,3-butadiene Derivatives
作者:Wei-Min Dai、Chi Wai Lau、Suet Ha Chung、Yun Dong Wu