Stereoselective Synthesis of 1,2-Disubstituted β-Amino Alcohols by Nucleophilic Addition to <i>N</i>-<i>tert</i>-Butanesulfinyl α-Alkoxyaldimines
作者:Jared W. Evans、Jonathan A. Ellman
DOI:10.1021/jo035224p
日期:2003.12.1
N-tert-Butanesulfinyl alpha-alkoxyaldimines are readily prepared from protected (S)-lactals without epimerization at the alpha-stereocenter. Addition of ethyl and phenyl Grignard reagents, as well as the titanium enolate of methyl acetate, to the N-tert-butanesulfinyl aldimines provides 1,2-disubstituted beta-amino alcohols in good yields (73-98%) and with high diastereoselectivities. Either syn- or anti-amino alcohol products can be obtained by the appropriate choice of alcohol protecting groups and/or reaction conditions. Finally, deprotection of the addition products provides straightforward access to either syn- or anti-1,2-amino alcohols.