Water → 6-Hydroxy-chroman-4-one

Participants

Reaction Steps

A mixture of 50.0 g (281 mmol) of 6-methoxychroman-4-one in 350 mL 48% HBr and 350 mL acetic acid was heated to reflux under N2. After 4 hours, the reaction mixture was cooled to room temperature in a Rotovap (trademark) and 1 L H2O was added. The suspension was kept at 0° C. overnight. The mixture was filtered, and the precipitate washed two times with H2O, two times with hexanes and then dried under vacuum to give 43.0 g of the title product as a dark purple/black solid. 93% yield.

Provenance & Evidence