反应详情

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 vacuum to provide 7-hydroxydihydrocoumarin. Yield: 1.83 g; melting point 133°-135.5° C.;

1. customcompletion of the reaction
2. filtrationThe reaction mixture was then filtered over a bed of Celite (Rohm and Haas Co., Philadelphia, Pa.)
3. customevaporated in vacuo
4. customto provide the crude product (4.5 g)
5. customA portion (2.5 g) of this material was recrystallized from toluene
6. customdried under vacuum