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Approaches to ?-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 ?-amino acids with both carboxyl and amino protection; hence, they are of great interest in peptide synthesis.

SUBMITTER: Chandrasekhar S

PROVIDER: S-EPMC3458766 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

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Approaches to α-amino acids via rearrangement to electron-deficient nitrogen: Beckmann and Hofmann rearrangements of appropriate carboxyl-protected substrates.

Chandrasekhar Sosale S Rao V Mohana VM

Beilstein journal of organic chemistry 20120829

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 w ...[more]

PMID: 23019476

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