ChemInform Abstract: Convenient Synthesis of Substituted Cyclopentenones via [3 + 2] Annulation of Allylidenetriphenylphosphorane with 1,2-Diacylethylenes: Application to Synthesis of (.+-.)-Methyl Dehydrojasmonate.

✍ Scribed by Y. HIMEDA; Y. TANAKA; I. UEDA; M. HATANAKA

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 43 KB
• Volume: 29
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199836120

✦ Synopsis

Convenient Synthesis of Substituted Cyclopentenones via [3 + 2] Annulation of Allylidenetriphenylphosphorane with 1,2-Diacylethylenes: Application to Synthesis of (±)-Methyl Dehydrojasmonate.

-Phosphoranes (I) undergo annulation with diacylethylenes (II) to give cyclopentadienes (III) and (IV) as mixtures of 1,3-and 1,4-dienes. They are converted upon mild conditions into the single form (V). An application of the annulation to the synthesis of (±)-methyl dehydrojasmonate (XI) is given. Annulation of (Ib) with acylmethylenemalonates yields cyclopentadienes in a highly regioselective manner, which are readily converted into cyclopentenones (XIII). Furthermore, (Ib) undergoes annulation with acylacetylene (XIV) to give the exomethylene cyclopentenone (XV). -(HIMEDA, Y.; TANAKA, Y.;