Evaluation of the Efficiency of the Chiral Quaternary Ammonium Salt β-Np-NAS-Br in the Organic-Aqueous Phase-Transfer Alkylation of a Protected Glycine Derivative

✍ Scribed by Takashi Ooi; Yukitaka Uematsu; Keiji Maruoka

• Book ID: 101390873
• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 64 KB
• Volume: 344
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/1615-4169(200206)344:3/4<288::aid-adsc288>3.0.co;2-8

✦ Synopsis

The inherent efficiency of the N-spiro C 2symmetric chiral quaternary ammonium salt (S,S)-3 [(S,S)-b-Np-NAS-Br] has been evaluated in the representative organic-aqueous liquid-liquid phase-transfer benzylation and allylation of glycine tert-butyl ester benzophenone Schiff base (1). This revealed the practical conditions for the asymmetric synthesis of both natural and unnatural a-amino acids, whose usefulness was demonstrated by the formal enantioselective synthesis of antibiotic l-azatyrosine.