作者:Wafaa M. Abdou、Ashraf A. Sediek
DOI:10.1016/s0040-4020(99)00940-0
日期:1999.12
Aminophosphine-ylides 4a and 4b were prepared in high yields by treating 3-acetyl coumarins 1a and 1b 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 1a and 1b yields the respective dialkyl phosphonates (1:4 addition) 12a,b, Conversely, dialkyl phosphonates react with the same species ln,b to give the tautomeric monophosphonates 17A reversible arrow 17B via both 1,4- and 1,2 additions, in contrast to earlier reports. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.