Use of Pseudoephedrine as a Practical Chiral Auxiliary for Asymmetric Synthesis
作者:Andrew G. Myers、Bryant H. Yang、Hou Chen、James L. Gleason
DOI:10.1021/ja00099a076
日期:1994.10
form tertiaryamides. In the presence of lithium chloride, the enolates of the corresponding pseudoephedrine amides undergo highly diastereoselective a1kylations with a wide range of alkyl halides to afford α-substituted products in high yields. These products can then be transformed in a single operation into highly enantiomerically enriched carboxylic acids, alcohols, and aldehydes. Lithium amidotrihydroborate
Synthesis of compounds with predetermined chirality
申请人:California Institute of Technology
公开号:US05488131A1
公开(公告)日:1996-01-30
A method for synthesizing enantiomerically enriched chemical intermediates with predetermined chirality is described. The method comprises formation of a pseudoephedrine amide, followed by stereoselective alkylation at the alpha carbon. The chiral auxiliary can then be cleaved off, affording chiral end products useful for further transformations. The enantiomeric enrichment of the chiral end products may exceed 98%, and the chiral auxiliary can be recovered. Novel amides of pseudoephedrine used in this method are also disclosed.