反应详情

A mixture of 7 parts of dimedone, 7 parts of 2,3-dihydrothiophene, 150 parts by volume of benzene and 0.7 parts of p-toluenesulfonic acid was refluxed by heating while stirring for 1 hour and 30 minutes and then allowed to stand at room temperature for 12 hours. The reaction mixture was washed with 50 parts by volume of water and then treated three times with 50 parts by volume of a 10% aqueous solution of sodium hydroxide. The aqueous layer was collected and the pH was adjusted to 2.0 with the addition of 6 N hydrochloric acid while maintaining the temperature thereof below 10° C. The light yellow colored crystals thus deposited were collected and purified by passing through a column containing a silica gel using a solvent mixture of chloroform and benzene (1:1) as a spreading agent to obtain 2-(2-tetrahydrothienyl)-3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one in a form of colorless fine crystals. The melting point was 97° to 99° C. The yield was 8 parts.

1. temperaturewas refluxed
2. temperatureby heating
3. waitto stand at room temperature for 12 hours
4. washThe reaction mixture was washed with 50 parts by volume of water
5. additiontreated three times with 50 parts by volume of a 10% aqueous solution of sodium hydroxide
6. customThe aqueous layer was collected
7. additionthe pH was adjusted to 2.0 with the addition of 6 N hydrochloric acid
8. temperaturewhile maintaining the temperature
9. custombelow 10° C
10. customThe light yellow colored crystals thus deposited were collected
11. custompurified
12. additioncontaining a silica gel using
13. additiona solvent mixture of chloroform and benzene (1:1) as a spreading agent