General approach to hydroxylated α-amino acids exploiting N-(tert-butoxycarbonyl)-2-(tert-butyldimethylsiloxy)pyrrole

Abstract

Racemic β-hydroxy-α-amino acids 7a, 7b and 10 of either threo or erythro configuration have been efficiently synthesized from simple aldehydes, utilizing N-(tert-butoxycarbonyl)-2-(tert- butyldimethylsiloxy)pyrrole (TBDMSOP) as a glycine-anion equivalent. Similar methodology, employing readily available aldehydo sugar precursors, has been successfully applied to syntheses of enantiomerically pure polyhydroxylated α-amino acids 14a–14f possessing diverse constitution and chirality.