Asymmetric Strecker-Type Reaction of α-Aryl Ketones. Synthesis of (<i>S</i>)-αM4CPG, (<i>S</i>)-MPPG, (<i>S</i>)-AIDA, and (<i>S</i>)-APICA, the Antagonists of Metabotropic Glutamate Receptors
作者:Dawei Ma、Hongqi Tian、Guixiang Zou
DOI:10.1021/jo981297a
日期:1999.1.1
Heating a mixture of alpha-aryl ketone with (R)-phenylglycinol produces a mixture of imine and 1,3-dioxazolidine. Treatment of this mixture with trimethylsilyl cyanide followed by transformation of nitrile to ester gives Strecker-type reaction products. The diastereoselectivity of the generated alpha-amino esters is from 2/1 to 7/1, and the (R,S)isomer is found as the major product. The (R,S) and (R,R)isomers can be separated by conversion to their N-Cbz or cyclization derivatives. Using this methodology, four antagonists of metabotropic glutamate receptors, (S)-alpha M4CPG, (S)-MPPG, (S)AIDA, and (S)-APICA, are synthesized.