(VII) was prepared from XI in% yo yield by condensation of the aldehyde with malonic acid according to the method of Adams and Mathieu. 6 Preliminary attempts to prepare VI1 by the Doebner procedure were unsuccessful and XI was recovered unchanged. A review of reactions of this type appearing in the literature4s6-6 indicated that the Knoevenagel and Doebner methods are often unsatisfactory when applied to 0-or p-hydrox ybenzaldehydes.
![ethyl 7-oxo-2,3-dihydrofuro[3,2-g]chromene-6-carboxylate Structure](https://image.chemsrc.com/caspic/113/73097-13-9.png)
![5-phenylfuro[3,2-g]chromen-7-one Structure](https://image.chemsrc.com/caspic/262/66486-61-1.png)
