Diisopropylamine → Ethyl 2-hydroxy-3,3-dimethylcyclohex-1-enecarboxylate

Temperature

-30 °C

Into a 500 mL round-bottomed flask was added diisopropylamine (3.5 mL) in ether (200 mL). After cooling to −30° C., butyllithium (16 mL) (1.6M in hexane) was added slowly. After stirring 30 minutes, the temperature was cooled to −5° C. 2,2-Dimethylcyclohexanone (3 g) was added slowly. The mixture was warmed up to 0° C. and stirred for 1 hour. After cooling to −5° C., hexamethylphosphoramide (8 mL) and ethyl carbonocyanidate (2.5 mL) were added. After stirring at −5° C. for 20 minutes, and warming to room temperature, the reaction was stirred for 1 hour. The mixture was poured into cold water, and the layers were separated. The aqueous layer was extracted with ether (3×20 mL). The combined the organic layers were washed with saturated aqueous NH4Cl (3×20 mL). After drying over Na2SO4, the mixture was filtered and the filtrate was concentrated. The crude product was purified by flash chromatography on silica with 0-10% ethyl acetate in hexanes to provide the title compound.

1. temperaturethe temperature was cooled to −5° C
2. temperatureThe mixture was warmed up to 0° C.
3. stirringstirred for 1 hour
4. temperatureAfter cooling to −5° C.
5. stirringAfter stirring at −5° C. for 20 minutes
6. temperaturewarming to room temperature
7. stirringthe reaction was stirred for 1 hour
8. customthe layers were separated
9. extractionThe aqueous layer was extracted with ether (3×20 mL)
10. washwere washed with saturated aqueous NH4Cl (3×20 mL)
11. dry with materialAfter drying over Na2SO4
12. filtrationthe mixture was filtered
13. concentrationthe filtrate was concentrated
14. customThe crude product was purified by flash chromatography on silica with 0-10% ethyl acetate in hexanes

ORD record

ord-40231d76146d44a3b528ea519f9407eb

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09045475B2