Establishing the Absolute Configuration of the Asbestinins: Enantioselective Total Synthesis of 11-Acetoxy-4-deoxyasbestinin D
作者:Michael T. Crimmins、J. Michael Ellis
DOI:10.1021/ja056921x
日期:2005.12.1
stereoselective synthesis of 11-acetoxy-4-deoxyasbestinin D (1) has been completed in 26 linear steps. The synthesis hinges on a selective glycolate aldol addition to establish the C-2 stereocenter, a ring-closing metathesis reaction to complete the oxonene, and an intramolecular Diels-Alder cycloaddition to establish the relative configuration at C-1, C-10, and C-14. This initial totalsynthesis of an asbestinin
An Intramolecular Diels−Alder Strategy for the Asbestinins: Enantioselective Total Syntheses of 11-Acetoxy-4-deoxyasbestinin D and Asbestinin-12
作者:Michael T. Crimmins、J. Michael Ellis
DOI:10.1021/jo0712695
日期:2008.3.1
[Graphics]The enantioselective total syntheses of 11-acetoxy-4-deoxyasbestinin D and asbestinin-12 have been completed. A glycolate aldol reaction provided a diene useful for ring-closing metathesis to form an oxonene, which was ultimately employed as a template to execute a highly stereoselective intramolecular Diels-Alder cycloaddition, forming the hydroisobenzofuran moiety. The absolute configuration of the asbestinin subclass was confirmed via these synthetic efforts.
A Direct Synthesis of Highly Substituted π‐Rich Aromatic Heterocycles from Oxetanes
作者:Alexander R. White、Ryan A. Kozlowski、Shiou‐Chuan Tsai、Christopher D. Vanderwal
DOI:10.1002/anie.201704119
日期:2017.8.21
five-membered heterocycles has driven the development of new methods for their synthesis for more than a century. Here, we disclose a general and reliable reaction manifold for the construction of highly substituted heterocycles through a facile Lewis-acid-catalyzed oxetane rearrangement. Notably, this methodology employs a keto-oxetane motif as a 1,4-dicarbonyl surrogate, which can be synthesized using
Syntheses of highly functionalised 6-substituted pteridines
作者:Donie Guiney、Colin L. Gibson、Colin J. Suckling
DOI:10.1039/b211564f
日期:2003.2.11
Methods for the synthesis of polyfunctional 6-substituted pteridines from the corresponding 6-aldehydes are described. Alkene, ester, ketone, amide, cyano, oxime, bromo, methoxy and dihydroxy functional groups have all been introduced principally through improved methodologies for Wittig reactions using 2-thioalkyl-6-formylpteridines as substrates. Further modification of the alkenes derived from the