BUTENOLIDE ANNELATIONS USING A MANGANESE(III) OXIDATION - A SYNTHESIS OF JOLKINOLIDE-E


DEMIR A., TANYELI C. , AKGUN H., CALISKAN Z., OZGUL E.

BULLETIN DE LA SOCIETE CHIMIQUE DE FRANCE, vol.132, no.4, pp.423-427, 1995 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 132 Issue: 4
  • Publication Date: 1995
  • Title of Journal : BULLETIN DE LA SOCIETE CHIMIQUE DE FRANCE
  • Page Numbers: pp.423-427
  • Keywords: (-)-JOLKINOLIDE E, MANGANESE(III) ACETATE OXIDATION, BUTENOLIDE ANNELATION, CARBOXYLIC-ACIDS, ACETATE, COMBINATION, KETONES

Abstract

A general procedure was developed for the annelation of a butenolide to an enone that highlighted a manganese(III) oxidation of an enone. The merit of this procedure was illustrated in a synthesis of (-)-jolkinolide E, ent-1, from (+)-manool 11. A potassium permanganate-mediated degradation of 11 and dehydration of an intermediate beta-hydroxyketone 12 according to a literature procedure afforded a tricyclic enone 13. Oxidation of 13 with manganese(III) acetate and chloropropionic acid regio- and stereoselectively furnished a C-12 alpha chloropropionyl ester 14. An Arbuzov reaction of 14 with triethylphosphite and an intramolecular Horner-Emmons cyclization of the resulting phosphonate 15 gave (-)-jolkinolide E, the structure of which was investigated in detail by NMR. This methodology was also applied to 4,4-dimethylcyclohex-2-en-1-one. This overall approach offers a general solution to the problem of butenolide annelation to enones.