title: Approaches to α-amino acids via rearrangement to electron-deficient nitrogen: Beckmann and Hofmann rearrangements of appropriate carboxyl-protected substrates.
abstract: The titled approaches were effected with various 2-substituted benzoylacetic acid oximes 3 (Beckmann) and 2-substituted malonamic acids 9 (Hofmann), their carboxyl groups being masked as a 2,4,10-trioxaadamantane unit (an orthoacetate). The oxime mesylates have been rearranged with basic Al(2)O(3) in refluxing CHCl(3), and the malonamic acids with phenyliodoso acetate and KOH/MeOH. Both routes are characterized by excellent overall yields. Structure confirmation of final products was conducted with X-ray diffraction in selected cases. The final N-benzoyl and N-(methoxycarbonyl) products are α-amino acids with both carboxyl and amino protection; hence, they are of great interest in peptide synthesis.
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: Sosale
authors.initials: S
authors.lastname: Chandrasekhar
authors.forename: V Mohana
authors.initials: VM
authors.lastname: Rao