A solution of 1-(2-acetyl-3-hydroxyphenoxy)-2-hydroxy-3-m-cresyloxypropane (25.3 g) in diethyl oxalate (30 ml) was added to a suspension of sodium ethoxide, prepared from sodium (6.0 g) and ethanol (60 ml), in dry ether (400 ml). The mixture was heated under reflux for 1.5 hours; the brown residue was poured onto ice (200 g) and acidified with a solution of acetic acid (24 ml) in water (160 ml). The ether layer was separated after adding more water (200 ml) and the aqueous layer extracted with ether (3 × 50 ml), adding the extracts to the organic layer. The solvent was then removed and the residue dissolved in absolute ethanol (200 ml) to which hydrochloric acid (10 drops) was added. The solution was heated under reflux for 30 minutes and the solvent removed to give a viscous brown oil, which solidified on standing. The oily crystals were filtered off and after recrystallization from aqueous ethanol gave 1-(2-carbethoxy-chromon-5-yloxy)-2 -hydroxy-3-m-cresyloxypropane (8.2 g) as a white solid, m.p. 72°-74°.
