Acetaldehyde, 2,2-dimethoxy- → 3-(4,7-Dihydroxy-5-methyl-2-oxo-2H-chromene-3-yl)-7-hydroxy-9-methyl-2-methoxy-2,3-dihydro-4H-furo[3.2-c]chromene-4-one

Beteiligte Stoffe

Reaktionsschritte

4,7-Dihydroxy-5-methylcoumarin (200 mg; 1.04 mmole) was dissolved in methanol (5 mL). A 60% aqueous dimethoxyacetaldehyde solution (792 μL; 8.7 mmole) was added and the reaction mixture was refluxed for 5 hours. By cooling to room temperature a white precipitate was precipitated, which was filtered off and washed with methanol. Obtained was the title compound in a 92% yield and of sufficient purity to be used in the next synthesis step:

Herkunft & Nachweise