Synthesis and reactions of phosphino- and phosphono substituted-coumarins

✍ Scribed by Wafaa M. Abdou; Ashraf A. Sediek

• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 1010 KB
• Volume: 55
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(99)00940-0

✦ Synopsis

Abstractz Aminophosphine-ylides 4a and 4b were prepared in high yields by treating 3-acetyl coumarins la and lb with trisdimethylaminophosphine 2. Chemical degradation reactions for the ylides 4a,b (e.g., formation of the phosphonium salt, Wittig reaction, hydrolysis) were suggested and illustrated. Reaction of trialkyl phosphites with 3-acetyl coumarins la and lb yields the respective dialkyl phosphonates (1:4 addition) 12a,b. Conversely, dialkyl phosphonates react with the same species la,b to give the tautomeric monophosphonates 17Ae 17B via both 1,4-and 1,2 additions, in contrast to earlier reports.