Sulfuric Acid → 7-Tert-butyl-8-hydroxy-5-methyl-1,2,3,4,4a,9a-hexahydro-9-fluorenone

Participants

Reaction Conditions

Reaction Steps

To 20 g of 8-hydroxy-5-methyl-1,2,3,4,4a,9a-hexahydro-9-fluorenone were added 200 ml of water and 200 ml of concentrated sulfuric acid and the mixture was stirred with heating at 90° C. At the same temperature, thereto was gradually added 53.71 g of N-tert-butylurea, followed by stirring with heating for 14 hours. Then, 10 g of N-tert-butylurea was further added, followed by further stirring at 90° C. for 5 hours. The reaction mixture was poured into 2 liters of water and extracted with chloroform. The chloroform layer was washed with saturated aqueous sodium chloride solution and then dried with magnesium sulfate. The solvent was distilled off and the residue was purified by a silica gel column chromatography (eluent: ethyl acetate:n-hexane=1:10) and thereafter recrystallized from n-hexane to obtain 19.67 g of 7-tert-butyl-8-hydroxy-5-methyl-1,2,3,4,4a,9a-hexahydro-9-fluorenone.

Provenance & Evidence