Carbon Dioxide → Benzopyran

Participants

Reaction Steps

A solution was prepared by dissolving 10 g (0.054 mole) of 1-acetyl-2-naphthol, 6.6 g (0.06 mole) of norcamphor and 8.7 g (0.10 mole) of morpholine in 300 cc of toluene, and the solution was boiled for 5 hours and water was separated. After termination of the reaction toluene was removed under reduced pressure, and the remaining chromanone compound was recrystallized from acetone, and the chromanon compound was dissolved in 200 cc of methanol and lithium aluminum hydride was added to the solution to form a chromanol compound. Then, 6.49 g of this chromanol compound was heated at 170° to 180° C. together with anhydrous copper sulfate in a carbon dioxide current for 10 minutes and the obtained brown viscous liquid was purified by the chromatography on silica gel to obtain 5.1 g of a chromene compound represented by the following formula: ##STR68##

Provenance & Evidence