Asymmetric aldol reactions with (+)-(S,S)-pseudoephedrine. Stereoselective synthesis of α-methyl β-hydroxy esters
作者:Jose L. Vicario、Dolores Badía、Esther Domínguez、Luisa Carrillo
DOI:10.1016/s0040-4039(98)02082-6
日期:1998.12
A new methodology for performing aldolreactions with an excellent degree of enantio- and diastereoselectivity was developed employing (+)-(S,S)-pseudoephedrine as chiral auxiliary.
Asymmetric Aldol Reactions Using (<i>S</i>,<i>S</i>)-(<i>+</i>)-Pseudoephedrine-Based Amides: Stereoselective Synthesis of α-Methyl-β-hydroxy Acids, Esters, Ketones, and 1,3-Syn and 1,3-Anti Diols
作者:Jose L. Vicario、Dolores Badía、Esther Domínguez、Mónica Rodríguez、Luisa Carrillo
DOI:10.1021/jo000035h
日期:2000.6.1
reactions is reported. The reaction of (S, S)-(+)-pseudoephedrine-derived propionamide enolates with several aldehydes yielded exclusively one of the four possible diastereomers in good yields, although transmetalation of the firstly generated lithium enolate with a zirconium(II) salt, prior to the addition of the aldehyde, is necessary in order to achieve high syn selectivity. The so-formed syn-alpha-methyl-beta-hydroxy