title: Preparation of a 24-nor-1,4-dien-3-one triterpene derivative from betulin: a new route to 24-nortriterpene analogues.
abstract: A new route to 24-nortriterpene derivatives with 2-hydroxy-Delta(1,4)-cyclohexadien-3-one A-rings from triterpene precursors has been demonstrated beginning with betulin to prepare derivatives of betulinic acid. The key steps in the transformation are a Suárez cleavage of the A-ring with a subsequent SmI(2)-mediated pinacol-type coupling to reclose the A-ring following removal of the C-24 carbon by oxidative cleavage.
authors.affiliation: Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Deng
authors.forename: John K
authors.initials: JK
authors.lastname: Snyder
mesh_terms: D029662:Betula / Q000737:chemistry*; D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D007938:Leukemia; D009682:Magnetic Resonance Spectroscopy; D008404:Massachusetts; D015394:Molecular Structure; D010051:Ovarian Neoplasms; D010084:Oxidation-Reduction; D024301:Plant Bark / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014315:Triterpenes / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects; D000094062:Betulinic Acid
chemical_list: D014315:Triterpenes; C002503:betulin; D000094062:Betulinic Acid