Organophosphorus chemistry 30 [1]. The behavior of 4-hydroxycoumarin toward methylenetriphenylphosphoranes (Wittig Reagents) and alkyl phosphites

✍ Scribed by Neven A. Ganoub; Mohamed R. H. Mahran

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 169 KB
• Volume: 9
• Category: Article
• ISSN: 1042-7163
• DOI: 10.1002/(sici)1098-1071(1998)9:4<427::aid-hc11>3.0.co;2-t

✦ Synopsis

4-Hydroxycoumarin (1) reacted with Wittig reagents (2) to give 4-benzoylmethylcoumarin (5A) or [3-(4-hydroxycoumarinyl)]carbonylmethylenetriphenylphosphorane (6) depending upon the nature of the phosphorus ylide used. Dialkyl phosphonates (3a,b) and trialkyl phosphites (4a,b) converted 1 into the respective O-alkyl ethers (11a,b). The groundstate structure of 1 is discussed in the light of experimental results. Compatible elementary and spectroscopic results were gained for the new products.