New Chiral Building Blocks from Tetrabromocyclopropene and Furan
作者:Phillip M. Pelphrey、Khalil A. Abboud、Dennis L. Wright
DOI:10.1021/jo048991c
日期:2004.10.1
cyclocondensation of tetrabromocyclopropene and furan leads directly to a halogenated oxabicyclo[3.2.1]octadiene derivative. Over the past several years, we have utilized these compounds as intermediates for natural product synthesis. Herein, we describe the preparation of nonracemic dibromoenone buildingblocksfrom the racemic cycloadduct. Conversion of the adduct to a mixture of tartrate-derived ketals followed
Versatile Oxabicyclic Synthons: Studies on C8-Oxygenated Eunicellin Diterpenes
作者:Dennis Wright、Phillip Pelphrey、David Bolstad
DOI:10.1055/s-2007-986667
日期:——
with a highly functionalized 8-oxabicyclo[3.2.1]octadiene system. The route features two sequential annulations to append a six- and five-membered ring onto the core structure followed by oxidative cleavage to reveal the eunicellin skeleton. Key to this strategy is a diastereo-selective intramolecular Nozaki-Hiyama-Kishi (NHK) closure to establish the correct relative stereochemical relationship at C6
Stereodivergent Resolution of Oxabicyclic Ketones: Preparation of Key Intermediates for Platensimycin and Other Natural Products
作者:Michael D. VanHeyst、E. Zachary Oblak、Dennis L. Wright
DOI:10.1021/jo4017502
日期:2013.10.18
An improved methodology for the preparation of enantiopure oxabicyclo[3.2.1]octadienes via a stereodivergent resolution is reported. High catalyst control proximal to the oxabridged stereocenter produces readily separable diastereomers in high yield (>92%) and with excellent optical purity (>95% ee). This resolution strategy is amenable to large-scale preparations, and the utility of the resolution was further demonstrated in the asymmetric preparation of a key intermediate used in the synthesis of the antibiotic (-)-platensimycin.
Bicyclo[3.2.1]octane Synthons from Cyclopropenes: Functionalization of Cycloadducts by Nucleophilic Additions
作者:Ravi S. Orugunty、Dennis L. Wright、Merle A. Battiste、Richard J. Helmich、Khalil Abboud
DOI:10.1021/jo035240m
日期:2004.1.1
counterparts derived through oxyallyl cation additions. As a first step towardutilizing these highlyversatile intermediates in synthesis, a study of the addition of various nucleophiles to the halogenated nucleus has been conducted. It has been found that these halogenated systems are amenable to a wide range of functionalizations in high yields and with good selectivities.
Efficient synthesis of bicyclo[3.2.1]octane-2,4-diones and their incorporation into potent HPPD inhibitors
作者:Myriam Baalouch、Alain De Mesmaeker、Renaud Beaudegnies
DOI:10.1016/j.tetlet.2012.11.081
日期:2013.2
Herein we report a very efficient access to a variety of bicyclic 1,3-diones as key intermediates to be incorporated into very potent HPPD inhibitors. In particular, we have developed a one-pot process for the synthesis of the bicyclo[3.2.1]octane-2,4-dione, the parent dione of Bicyclopyrone. (c) 2012 Elsevier Ltd. All rights reserved.