Umbelliferone → 7-Hydroxychromanone

Beteiligte Stoffe

Reaktionsschritte

A solution of 7-hydroxycoumarin (5.0 g, 0.031 mol; Aldrich Chemical Company) in absolute ethanol (200 mL) was hydrogenated under pressure in a Parr apparatus over 10% Pd/C (Catalyst; 500 mg, 50% water; Kodak Inc., Rochester, N.Y.) for 24 hours at 55° C. Thin layer chromatography (TLC; Silica gel: EtOAc/hexane: 1:1) showed completion of the reaction. The reaction mixture was then filtered over a bed of Celite (Rohm and Haas Co., Philadelphia, Pa.) and evaporated in vacuo to provide the crude product (4.5 g). A portion (2.5 g) of this material was recrystallized from toluene and dried under vaccuum to provide 7-hydroxydihydrocoumarin. Yield: 1.83 g; melting point 133°-135.5° C.;

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