Chromocarb → 3,4-dihydro-2H-1-benzopyran-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

4-Oxo-4H-chromene-2-carboxylic acid (Aldrich, 3.0 g, 15.8 mmol) was added to a mixture of acetic acid (30 mL) and 10% palladium on carbon (0.3 g) in a Parr shaker. The glass reactor was sealed and flushed with nitrogen, and it was pressurized with hydrogen (60 psi). The mixture was shaken at 70° C. for 2.5 hours. The mixture was filtered and the solids were rinsed with methanol. The filtrate was concentrated under reduced pressure and chromatographed on silica gel eluting with 0-to-10% methanol in ethyl acetate to afford the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 2.04 (m, 1H), 2.14 (m, 1H), 2.63 (dt, 1H), 2.78 (dt, 1H), 4.76 (dd, 1H), 6.80 (m, 2H), 7.05 (m, 2H). MS (ESI) m/z 177.09 (M−H)−.

Provenance & Evidence