rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Stereoselective syntheses of alpha, beta-diamino acids
  name:
    name part: Nace, Vaughn Mark
    role:
      role term: creator
  name:
    name part: Gunn, J. M.
    role:
      role term: degree committee member.
  name:
    name part: Harding, K. E.
    role:
      role term: degree supervisor.
  name:
    name part: Hogg, J. L.
    role:
      role term: degree committee member.
  name:
    name part: Newcomb, M. E.
    role:
      role term: degree committee member.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1984
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xi, 121 leaves : illustrations ; 29 cm
  abstract: A method for the threo-stereoselective synthesis of (alpha),(beta)-diamino acids has been developed. This method was applied to the synthesis of (5-chloro-2-piperidinyl)glycine (streptolutine) and analogs of streptolutine. These amino acids, especially streptolutine, are similar in structure to the well-known antineoplastic compound 593-A, and may possess significant biological activity. Acylation of the lithio-dianion of methyl hippurate with 4-pentenoyl chloride gave methyl 2-benzoylamino-3-oxo-6-heptenoate. The (beta)-keto ester was converted to methyl 2-benzoylamino-3-amino-6-heptenoate via a reductive amination process using NH(,4)OAc and NaBH(,3)CN. This (beta)-amino ester was formed in a 2:1 erythro:threo ratio of diastereomers rather than the desired threo-selective direction. This shortcoming was circumvented by incorporating the alpha benzamide and beta amino groups into an imidazolidinone ring system, which can be epimerized at the alpha center to give the more stable trans-substituted system (threo). Cleavage of the ring and protection of the amine and acid groups gave methyl 2,3-di-(benzyloxycarbonylamino)-6-heptenoate with a ratio of threo to erythro isomers of approximately 4:1. Treatment with mercuric acetate followed by reduction and protecting group cleavage led to 2-amino-2-(trans-5-methyl-2-pyrrolidinyl)-acetic acid. Treatment of the same (alpha),(beta)-CBz ester with Hg(OAc)(,2), followed by refunctionalization of the resulting organomercurial intermediate and CBz group cleavage resulted in methyl 2-amino-2-(trans-5-iodomethyl-2-pyrrolidinyl)acetate dihydrobromide. This derivative of a potentially biologically active amino acid was converted to streptolutine methyl ester and a 5-membered ring isomer of streptolutine methyl ester by treatment of the iodomethyl amino ester with base to form the corresponding bicyclic azirdine, and ring-opening with HCl gas.
  note: "Major subject: Chemistry."
  note: Typescript (photocopy).
  note: Vita.
  note: Ph. D. in Philosophy Texas A & M University 1984
  note: Includes bibliographical references (leaves 117-120).
  subject:
    topic: Amino acids
    topic: Synthesis
  subject:
    topic: Chemistry
  identifier: http://proxy.library.tamu.edu/login
  identifier: https://hdl.handle.net/1969.1/DISSERTATIONS-438986
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: https://hdl.handle.net/1969.1/DISSERTATIONS-438986
  record info:
    record content source: TXA
    record creation date: 870113
    record change date: 20220103135031.0
    record identifier: in00000415037
    language of cataloging:
      language term: eng