反应详情

温度

-20 °C

In 100 ml. of dry tetrahydrofuran is dissolved 3.6 g. of 1,3-dithian and while the solution is chilled to -30° C. in nitrogen gas streams and stirred, 10 ml. of a 20% solution of n-butyl lithium in hexane is added dropwise over a period of about 15 minutes. After the dropwise addition has been completed, the solution is stirred at that temperature for 2 hours and, then, at -5° C. for 30 minutes. The solution is chilled again to -20° C and, under stirring, a solution of 7.1 g. of 4-benzoylindan-1-one in 75 ml. of dry tetrahydrofuran is added dropwise. After the dropwise addition has been completed, the mixture is stirred at that temperature for 1 hour, after which it is allowed to stand at 0° C. overnight. Then, the solvent is distilled off under reduced pressure. To the residue is added 15 ml. of dilute hydrochloric acid, followed by extraction with ether. The extract is washed with water and aqueous sodium chloride and, then, dried. The solvent is distilled off under reduced pressure and the residue is purified by column chromatography on silica gel (500 g. silica gel, eluted with a 20:1 mixture of benzene and ethyl acetate). The described procedure gives 2-(4-benzoyl-1-hydroxy-1-indanyl)-1,3-dithian as an oily product. The infrared absorption spectrum (neat) of this product is in good agreement with the assumed structure, absorbing at 1660 cm-1 (ketone) and 3450 cm-1 (hydroxyl).

1. additionAfter the dropwise addition
2. stirringthe solution is stirred at that temperature for 2 hours
3. stirringunder stirring
4. additionAfter the dropwise addition
5. stirringthe mixture is stirred at that temperature for 1 hour
6. waitto stand at 0° C. overnight
7. distillationThen, the solvent is distilled off under reduced pressure
8. additionTo the residue is added 15 ml
9. extractionof dilute hydrochloric acid, followed by extraction with ether
10. washThe extract is washed with water and aqueous sodium chloride
11. customdried
12. distillationThe solvent is distilled off under reduced pressure
13. customthe residue is purified by column chromatography on silica gel (500 g
14. washsilica gel, eluted with a 20:1 mixture of benzene and ethyl acetate)