The Exceptional Chelating Ability of Dimethylaluminum Chloride and Methylaluminum Dichloride. The Merged Stereochemical Impact of α- and β-Stereocenters in Chelate-Controlled Carbonyl Addition Reactions with Enolsilane and Hydride Nucleophiles
作者:David A. Evans、Brett D. Allison、Michael G. Yang、Craig E. Masse
DOI:10.1021/ja011337j
日期:2001.11.1
beta-disubstituted aldehydes concludes that the syn aldehyde diastereomer possesses the arrangement of stereocenters wherein the alpha- and beta-substituents impart a reinforcing facial bias upon the aldehyde carbonyl. Aldol reactions of syn aldehydes were thus observed to proceed with uniformly excellent diastereofacial selectivity. Aldol reactions of the corresponding anti aldehydes containing opposing
Total Synthesis of the Oxopolyene Macrolide (−)-Marinisporolide C
作者:Luiz C. Dias、Emílio C. de Lucca
DOI:10.1021/acs.orglett.5b03352
日期:2015.12.18
The first totalsynthesis of (−)-marinisporolide C was performed in 25 steps (longest linear sequence) and an overall yield of 1%. Due to the high degree of convergence and robustness, the C9–C35 fragment that corresponds to the polyol portion was obtained in gram quantity. Highlights of this synthesis include five highly stereoselective aldol reactions responsible for the construction of five C–C
The first total synthesis of (−)-marinisporolide C is described, which establishes unequivocally the relative and absolute configuration of this oxopolyene macrolide. Key features of this synthesis include a series of highly stereoselective aldol reactions followed by directed reductions to build the polyol domain, a Stille cross-coupling reaction to assemble the polyene, and an intramolecular Hor