title: The Dakin-West reaction of N-alkoxycarbonyl-N-alkyl-alpha-amino acids employing trifluoroacetic anhydride.
abstract: The Dakin-West reaction of N-alkoxycarbonyl-N-alkyl-alpha-amino acids (1a-j) with trifluoroacetic anhydride in the presence of pyridine gave alpha-amido trifluoromethyl ketones (2a-j), in which probable intermediates were mesoionic 1,3-oxazolium-5-olates (munchnones). The diastereoselective reduction of 2a-f with NaBH4 gave the threo-aminoalcohols (5a-f), which may be explained by the Felkin-Anh model. This was confirmed by converting 5a-f into trans-5-trifluoromethyl-2-oxazolidinones (6a-f) in good yields.
authors.affiliation: Faculty of Pharmaceutical Sciences, Josai University, Saitama, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kawase
authors.forename: M
authors.initials: M
authors.lastname: Hirabayashi
authors.forename: H
authors.initials: H
authors.lastname: Kumakura
authors.forename: S
authors.initials: S
authors.lastname: Saito
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000089:Acetic Anhydrides; D000596:Amino Acids / Q000138:chemical synthesis* / Q000494:pharmacology; D001894:Borohydrides; D003500:Cyclization; D005463:Fluoroacetates; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D011725:Pyridines / Q000737:chemistry
chemical_list: D000089:Acetic Anhydrides; D000596:Amino Acids; D001894:Borohydrides; D005463:Fluoroacetates; D007202:Indicators and Reagents; D011725:Pyridines; C017958:trifluoroacetic anhydride