The chemistry of zerumbone. Part 5: Structural transformation of the dimethylamine derivatives

Takashi Kitayama, Taketo Yokoi, Yasushi Kawai, Richard K. Hill, Masanori Morita, Tadashi Okamoto, Yukio Yamamoto, Valery V. Fokin, K. Barry Sharpless, Seiji Sawada

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Zerumbone (1) and its 6,7-epoxide (2) react with ammonia and dimethylamine regio- and stereospecifically, affording monoamines 3, 4, 7 and 8. All adducts have the same relative configuration at C2 and C3. The conjugate amination is thermodynamically controlled to arrive at a single diastereomer. At 15°C 7 reacts with cyanide to give aminonitrile 10 as the single product, while at 30°C, acyclic aminonitrile 11 is also formed. The reaction with 8 affords at 0°C bicyclic aminonitrile 12 of the asteriscane skeleton, while at 30°C or higher temperature, mixtures of 12 and tricyclic nitriles 13 and 13′ are obtained. Refluxing of 7, 8 and 10 in aqueous acetonitrile promotes scission of the zerumbone ring by retro-Mannich reaction to provide acyclic aldehydes 16-18, respectively. The dimethylamino group of 7, 8 and 10 is eliminated stereospecifically by Cope- and base-catalyzed eliminations to regenerate the zerumbone skeleton in the products 1, 2 and 21. Cope elimination of 12 results in a mixture of 13 and 13′ by deaminative transannular etherification.

Original languageEnglish
Pages (from-to)4857-4866
Number of pages10
JournalTetrahedron
Volume59
Issue number26
DOIs
Publication statusPublished - 23 Jun 2003
Externally publishedYes

Keywords

  • Asteriscane
  • Cope elimination
  • Retro-Mannich
  • Sesquiterpene
  • Transannular
  • Zerumbone

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

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  • Cite this

    Kitayama, T., Yokoi, T., Kawai, Y., Hill, R. K., Morita, M., Okamoto, T., Yamamoto, Y., Fokin, V. V., Sharpless, K. B., & Sawada, S. (2003). The chemistry of zerumbone. Part 5: Structural transformation of the dimethylamine derivatives. Tetrahedron, 59(26), 4857-4866. https://doi.org/10.1016/S0040-4020(03)00667-7