Diazomethane → 2-(2-Tetrahydrothienyl)-3-methoxy-5,5-dimethyl-2-cyclohexen-1-one

Participants

Reaction Steps

To 500 parts by volume of an ether solution of diazomethane prepared using 47 parts of N-nitroso urea and 140 parts by volume of a 40% aqueous solution of potassium hydroxide in a conventional manner, 17.7 parts of 2-(2-tetrahydrothienyl)-3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one was added little by little over a period of 20 minutes. After stirring for 15 hours at room temperature, the unreacted diazomethane was decomposed by the addition of 5 parts of acetic acid and washed with 1 N aqueous sodium hydroxide solution and then with a saturated aqueous sodium chloride solution followed by drying. After removing ether by distillation, the residue was passed through a column containing a silica gel using a solvent mixture of chloroform and benzene (1:3) as a spreading agent. Upon recrystallization of the raw product from a solvent mixture of benzene and n-hexane, 2-(2-tetrahydrothienyl)-3-methoxy-5,5-dimethyl-2-cyclohexen-1-one was obtained in the form of colorless scale-like crystals. The melting point was 111° to 112° C. The yield was 5.7 parts.

Provenance & Evidence