反应详情

温度

0 °C

1-(2,2-dimethoxyethyl)cyclopent-3-enol (13.5 g, 78 mmol) was dissolved in DCM (250 mL). This was chilled to 0° C. under nitrogen and 2,4,6-trimethylpyridine (42 mL, 314 mmol) was added dropwise over 10 minutes. Tert-butyldimethylsilyl trifluoromethanesulfonate (18 mL, 78 mmol) was added dropwise via syringe very slowly over 20 minutes keeping the internal temperature below 5° C. The reaction was allowed to come to RT. By TLC (20% EtOAc/hexanes; KMnO4 stain), the starting material was completely consumed (˜2 hours). The reaction was then chilled back to 0° C. and triethylsilyl trifluoromethanesulfonate (35 mL, 157 mmol) was added in dropwise over a 10 minute period. This was allowed to stir at 0° C. for 1 hour before adding water (250 mL). The ice bath was removed and this mixture was stirred vigorously for ˜18 hours. The reaction was poured into a seperatory funnel and the DCM layer was separated. The organic was washed with dilute aqueous HCl, brine, dried over sodium sulfate, filtered and concentrated to afford a yellow oil which was flashed on silica by gradient eluting with hexanes to 20% EtOAc/hexanes over a 40 minute period. Product fractions were combined to afford the title compound.

1. customthe internal temperature below 5° C
2. customto come to RT
3. customBy TLC (20% EtOAc/hexanes; KMnO4 stain), the starting material was completely consumed (˜2 hours)
4. temperatureThe reaction was then chilled back to 0° C.
5. customThe ice bath was removed
6. stirringthis mixture was stirred vigorously for ˜18 hours
7. additionThe reaction was poured into a seperatory funnel
8. customthe DCM layer was separated
9. washThe organic was washed with dilute aqueous HCl, brine
10. dry with materialdried over sodium sulfate
11. filtrationfiltered
12. concentrationconcentrated
13. customto afford a yellow oil which
14. washby gradient eluting with hexanes to 20% EtOAc/hexanes over a 40 minute period