Acetone → HCID 59317564, compound

Temperature

-20 °C

The resulting lithium carbamate compound (Compound 2a) (8.47 g, 42.60 mmol) was put into a Schlenk flask. Thereafter, tetrahydrofuran (4.6 g, 63.9 mmol) and diethylether (45 mL) were added thereto in this order. The Schlenk flask was immersed in an acetone/small amount of dry ice cooling bath at −20° C., and shaken for 30 minutes, and then tert-BuLi (25.1 mL, 1.7 M, 42.60 mmol) was added thereto. At that time, the reaction mixture turned red. While maintaining the temperature at −20° C., the reaction mixture was stirred for 6 hours. A CeCl3.2LiCl solution of tetrahydrofuran (129 mL, 0.33 M, 42.60 mmol) and tetramethylcyclopentanone (5.89 g, 42.60 mmol) were mixed in a syringe, and then introduced into the flask under nitrogen atmosphere. The flask was gradually warmed to ambient temperature, and one hour later, the incubator was removed, and the temperature was maintained at ambient temperature. Then, water (15 mL) was added into the flask, and ethyl acetate was added thereto to obtain a filtrate. The filtrate was transferred into a separatory funnel, and hydrochloric acid (2 N, 80 mL) was added thereto, and the separatory funnel was shaken for 12 minutes. Thereafter, a saturated, aqueous sodium carbonate solution (160 mL) was added thereto to neutralize the solution, and then an organic phase was extracted. To this organic phase, anhydrous magnesium sulfate was added to remove moisture, the resultant was filtered and taken, and the solvent was removed. The resulting filtrate was purified by column chromatography using a hexane/ethyl acetate (v/v, 10:1) solvent to obtain a yellow oil. The yield was 40%.

1. stirringthe reaction mixture was stirred for 6 hours
2. additionintroduced into the flask under nitrogen atmosphere
3. temperatureThe flask was gradually warmed to ambient temperature
4. customone hour later, the incubator was removed
5. temperaturethe temperature was maintained at ambient temperature
6. additionThen, water (15 mL) was added into the flask, and ethyl acetate
7. additionwas added
8. customto obtain a filtrate
9. customThe filtrate was transferred into a separatory funnel
10. stirringthe separatory funnel was shaken for 12 minutes
11. extractionan organic phase was extracted
12. additionTo this organic phase, anhydrous magnesium sulfate was added
13. customto remove moisture
14. filtrationthe resultant was filtered
15. customthe solvent was removed
16. customThe resulting filtrate was purified by column chromatography
17. customto obtain a yellow oil

ORD record

ord-84571d60c5ea429e826a92bb0a859198

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09120836B2