HCID 355613, compound → HCID 20251925, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of the chromanone 2--2 (2.13 g, 9.25 mmol, 1 equiv) and 10% palladium on carbon (320 mg, 0.301 mmol, 0.0325 equiv) in acetic acid (20 mL) was heated at 70° C. under a hydrogen balloon for 16 h. After cooling to 23° C., the solids were removed by filtration through a pad of Celite® and were washed with ethyl acetate (100 mL). The filtrate was concentrated and the residue was purified by flash column chromatography (5% ethyl acetate in hexanes) to provide the benzopyran 2-3 as a colorless oil as well as recovered starting chromanone; 1H NMR (400 MHz, CDCl3), δ: 7.09 (m, 2H, ArH), 6.85 (m, 2H, ArH), 3.78 (m, 1H, OCH), 2.83 (m, 2H, ArCH2), 2.03 (m, 2H, ArCH2CH2 and CyH), 1.90-1.70 (m, 5H, ArCH2CH2 and CyH), 1.65 (m, 1H, CyH), 1.40-1.10 (m, 5H, CyH); TLC (5% ethyl acetate-hexanes), Rf =0.57 (UV).

Provenance & Evidence