Oxonium Ion Elektrophiles: Synthesis of the Hypotensive Oudenone.

Article abstract of DOI:10.1021/jo00220a032

The hypotensive oudenone (1) has been synthesized through the intermediacy of oxonium ion 4.Acid-catalyzed C-alkylation of 1,3-cyclopentanedione (3) with 5-propyltetrahydro-2-furanol (6b) afforded dihydrooudenone 2b.In contrast, alkylation of 3 with 2-chloro-5-propyltetrahydrofuran (7b) was unsuccessful.Unsaturation was introduced into 2b by treatment with N-(phenylthio)succinimide to produce 10 followed by oxidation to the corresponding sulfoxide and elimination of phenylsulfenic acid, which produced oudenone(1).