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

4-Hydroxycoumarin (1) reacted with Wittig reagents (2) to give 4-benzoylmethylcoumarin(5A) or [3-(4-hydroxycoumarinyl)]carbonylmethyl-enetriphenylphosphorane (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 ground-state structure of 1 is discussed in the light of experimental results. Compatible elementary and spectroscopic results were gained for the new products. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:427–431, 1998