Hydrochloric Acid → 2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-7-ol

Participants

Reaction Steps

2,3-Dihydro-2,2-dimethyl-7-hydroxy-4H-benzo[b]pyran-4-one (9.98 g), amalgamated zinc dust (50.0 g), 5 N hydrochloric acid (400 ml) and glacial acetic acid (100 ml) were stirred and refluxed for 4 hours then stirred at room temperature for 18 hours. The reaction mixture was extracted with diethyl ether, washed with water, dried and evaporated in vacuo to afford a dark red oil which was distilled to give 2,3-dihydro-2,2-dimethyl-7-hydroxy-4H-benzo[b]pyran (4.22 g) as an orange oil, bp 138°-146° C. (0.02 mm).

Provenance & Evidence