反应详情

温度

-78 °C

The product from step (a) (102.6 g) was dissolved in tetrahydrofuran (600 ml) and treated with N-bromosuccinimide (89 g) at -78° C. under nitrogen for 15 minutes. The reaction was allowed to come to ambient temperature over one hour, concentrated, diluted with hexane, filtered and the solvent removed. The residue was dissolved in tetrahydrofuran (600 ml), cooled to -78° C., and tert-butyl lithium in pentane (588 ml 1.7M) was added. After one hour elemental sulfur (16 g) was added and the mixture was stirred for one hour at ambient temperature. The reaction was cooled to -78° C. and triisopropyl silyl chloride (98 g) was added and the reaction was allowed to warm to room temperature. After 24 hrs the solvent was removed under reduced pressure and the residue in diethyl ether was washed with water, dried over sodium sulfate, filtered, concentrated and distilled at 160°-205° C. (0.2 mm) to give a colorless viscous oil (119.8 g). 1H NMR is consistent with proposed structure.

1. concentrationconcentrated
2. additiondiluted with hexane
3. filtrationfiltered
4. customthe solvent removed
5. dissolutionThe residue was dissolved in tetrahydrofuran (600 ml)
6. additiontert-butyl lithium in pentane (588 ml 1.7M) was added
7. additionAfter one hour elemental sulfur (16 g) was added
8. temperatureThe reaction was cooled to -78° C.
9. additiontriisopropyl silyl chloride (98 g) was added
10. temperatureto warm to room temperature
11. customAfter 24 hrs the solvent was removed under reduced pressure
12. washthe residue in diethyl ether was washed with water
13. dry with materialdried over sodium sulfate
14. filtrationfiltered
15. concentrationconcentrated
16. distillationdistilled at 160°-205° C. (0.2 mm)