Pseudoephedrine as a Chiral Auxiliary for Asymmetric Michael Reactions: Synthesis of 3-Aryl-δ-lactones
作者:Jacqueline H. Smitrovich、Geneviève N. Boice、Chuanxing Qu、Lisa DiMichele、Todd D. Nelson、Mark A. Huffman、Jerry Murry、James McNamara、Paul J. Reider
DOI:10.1021/ol0259847
日期:2002.5.1
[reaction: see text] The asymmetric Michael reaction of pseudoephedrine amides is reported. The 1,5-dicarbonyl products are converted to 3-aryl-delta-lactones in a two-step reduction/lactonization sequence. This method provides access to enantiomerically enriched trans-3,4-disubstituted delta-lactones.
Michael Reactions of Pseudoephedrine Amide Enolates: Effect of LiCl on Syn/Anti Selectivity
作者:Jacqueline H. Smitrovich、Lisa DiMichele、Chuanxing Qu、Geneviève N. Boice、Todd D. Nelson、Mark A. Huffman、Jerry Murry
DOI:10.1021/jo035564a
日期:2004.3.1
asymmetric Michael reaction of pseudoephedrine amide enolates changes dramatically in the presence of LiCl. Reaction of the enolate in the absence of LiCl results in formation of the antiMichael adduct with high selectivity, whereas in the presence of lithium chloride the syn adduct is favored. This method provides access to enantiomerically enriched trans-3,4-disubstituted δ-lactones from the anti Michael