Derivate der Ketipinsäure, II. Ketipinsäuredilacton und verwandte Verbindungen

✍ Scribed by Stachel, Hans-Dietrich ;Jungkenn, Michael ;Koser-Gnoss, Christiane ;Poschenrieder, Hermann ;Redlin, Jutta

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 465 KB
• Volume: 1994
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.199419940921

✦ Synopsis

Derivatives of Ketipic Acid, II. – Ketipic Acid Dilactone and Related Compounds

The highly reactive title compound 7 was prepared by thermal decomposition of the disguised oxalylbisketene 6. Ring opening of 7 with nucleophiles leads to γ‐alkylidenetetronic acids 4. α‐Substituted derivatives of 4a give rise to unsymmetrical dilactones 9a–c and the dibromodilactone 9d. The alkylidenetetronic acids are stabilized in the E configuration by hydrogen bridges. The pairs of isomeric (E)‐ and (Z)‐alkylidenetetronic acids 3 and 4 show characteristic spectral differences.