Efficient Transesterification/Acylation Reactions Mediated by <i>N</i>-Heterocyclic Carbene Catalysts
作者:Gabriela A. Grasa、Tatyana Güveli、Rohit Singh、Steven P. Nolan
DOI:10.1021/jo0267551
日期:2003.4.1
Imidazol-2-ylidenes, a family of N-heterocyclic carbenes (NHC), are efficient catalysts in the transesterification involving numerous esters and alcohols. Low catalyst loadings of aryl- or alkyl-substituted NHC catalysts mediate the acylation of alcohols with enol acetates in short reaction times at room temperature. Commercially available and more difficult to cleave methyl esters react with primary
Total Synthesis and Proof of Relative Stereochemistry of (−)-Aureonitol
作者:Peter J. Jervis、Liam R. Cox
DOI:10.1021/jo801338t
日期:2008.10.3
Two trisubstituted epimeric tetrahydrofurans, 1 and 2, have been synthesized in order to confirm the relative stereochemistry in the natural product aureonitol. The key step in the synthesis of 1 and 2 involved a stereoselective intramolecular allylation of an allylsilane with an aldehyde, which introduced the stereotriad in the five-membered ring. The major tetrahydrofuran diastereoisomer 18 from