Diisopropylamine → Methyl 1-(but-3-en-1-yl)cyclopentane-1-carboxylate

Temperature

0 °C

To a solution of diisopropylamine (10.5 mL, 75 mmol) in tetrahydrofuran (100 mL) pre-cooled to −75° C. was added a 2.5 M solution of n-butyllithium in hexanes (30 mL, 75 mmol) dropwise. Following addition, the reaction mixture was warmed to 0° C. for 30 min and then re-cooled to −75° C. To the mixture was added a solution of methyl cyclopentane carboxylate (8 g, 62 mmol) in tetrahydrofuran (40 mL) dropwise. After stirring for 30 min, a solution of 4-bromo-1-butene (8.2 mL, 81 mmol) in HMPA (6 mL) was added dropwise. The cooling bath was removed to allow the mixture to warm to 20° C. After 1.5 h, the reaction mixture was poured into ice/H2O (200 mL). The two layers were separated and the aqueous layer was extracted with Et2O (100 mL). The organic solutions were combined and dried over K2CO3, filtered and concentrated to afford the 12.1 g of the title compound as an oil. LC/MS: RT=3.57 min. MS (ESI) m/z=183 (M+H+)

1. additionaddition
2. temperaturere-cooled to −75° C
3. customThe cooling bath was removed
4. temperatureto warm to 20° C
5. waitAfter 1.5 h
6. additionthe reaction mixture was poured into ice/H2O (200 mL)
7. customThe two layers were separated
8. extractionthe aqueous layer was extracted with Et2O (100 mL)
9. dry with materialdried over K2CO3
10. filtrationfiltered
11. concentrationconcentrated

ORD record

ord-1d9ede22bd624743847ed4c50bd00629

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08735385B2