Tetrahydrofuran → HCID 86681318, compound

Temperature

-35 °C

To a solution of (1S,5R)-2-(2-methoxyethyl)-6,6-dimethylbicyclo[3.1.1]hept-2-ene (940 mg) in tetrahydrofuran (5 mL) was added dropwise 9-borabicyclo[3.3.1]nonane (0.5 M in tetrahydrofuran, 10.43 mL). The reaction mixture was heated to reflux overnight, then cooled to −35° C. and then placed under a CO atmosphere (1 atm). LiAl(OtBu)3H (1M in tetrahydrofuran, 5.21 mL) was added dropwise over 30 minutes. Following the addition, the reaction mixture was stirred for 1.5 hours under CO (1 atm), during which time the reaction temperature was increased to 0° C. The mixture was warmed to room temperature and stirred for 45 minutes, then the system was flushed with argon and a buffer solution (5.28 g NaH2PO4 and 6.86 g K2HPO4 in 20 mL water) was added. The flask was chilled in a −10° C. cooling bath and the reaction was quenched by dropwise addition of 30% aqueous H2O2 solution (2.2 mL), then warmed to room temperature and stirred for 15 minutes. The reaction mixture was partitioned between water (50 mL) and ethyl acetate (3×75 mL). The organic phase was then washed with 10% Na2S2O3 (3×50 mL) and brine (50 mL), then dried (MgSO4), filtered, and concentrated. The crude product was purified by flash chromatography on silica gel eluting with 0 to 50% ethyl acetate in hexanes to give the title compound.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux overnight
3. additionthe addition
4. temperaturewas increased to 0° C
5. temperatureThe mixture was warmed to room temperature
6. stirringstirred for 45 minutes
7. customthe system was flushed with argon
8. additiona buffer solution (5.28 g NaH2PO4 and 6.86 g K2HPO4 in 20 mL water) was added
9. temperatureThe flask was chilled in a −10° C.
10. temperaturecooling bath
11. customthe reaction was quenched by dropwise addition of 30% aqueous H2O2 solution (2.2 mL)
12. temperaturewarmed to room temperature
13. stirringstirred for 15 minutes
14. customThe reaction mixture was partitioned between water (50 mL) and ethyl acetate (3×75 mL)
15. washThe organic phase was then washed with 10% Na2S2O3 (3×50 mL) and brine (50 mL)
16. dry with materialdried (MgSO4)
17. filtrationfiltered
18. concentrationconcentrated
19. customThe crude product was purified by flash chromatography on silica gel eluting with 0 to 50% ethyl acetate in hexanes

ORD record

ord-7a767faa0692432aad5fa1aba32e3acd

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08940737B2