Tetrahydrofuran → Benzyl 3-hydroxycyclopentanecarboxylate

Temperature

0 °C

A solution of (−)-α-pinene (5.80 g, 42.6 mmol) in THF (10 mL) was cooled to 0° C. and a solution of borane-Me2S (10N, 1.5 mL, 15 mmol) was added. The mixture was stirred for 4 h at 0° C. and benzyl cyclopent-3-enecarboxylate (3.5 g, 17 mmol) was added. The reaction mixture was allowed to warm to ambient temperature and stirred overnight. The mixture was cooled to 0° C. again and quenched with water (2 mL) and aqueous NaOH (3N, 15 mL). Then 30% hydrogen peroxide (20 mL) was added dropwise. The mixture was stirred for 1 h at 0° C. and diluted with water (20 mL) and EtOAc (50 mL). The two layers were separated and the aqueous phase was extracted with EtOAc (50 mL×3). The combined organic phases were washed with brine (200 mL×3), dried over anhydrous sodium sulfate, and concentrated. The residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4) to afford benzyl 3-hydroxycyclopentanecarboxylate (1.4 g, 37% yield).

1. temperatureto warm to ambient temperature
2. stirringstirred overnight
3. temperatureThe mixture was cooled to 0° C. again
4. customquenched with water (2 mL) and aqueous NaOH (3N, 15 mL)
5. additionThen 30% hydrogen peroxide (20 mL) was added dropwise
6. stirringThe mixture was stirred for 1 h at 0° C.
7. additiondiluted with water (20 mL) and EtOAc (50 mL)
8. customThe two layers were separated
9. extractionthe aqueous phase was extracted with EtOAc (50 mL×3)
10. washThe combined organic phases were washed with brine (200 mL×3)
11. dry with materialdried over anhydrous sodium sulfate
12. concentrationconcentrated
13. customThe residue was purified by flash column chromatography on silica gel (EtOAc/hexane=1:4)

ORD record

ord-1af963ab8ff943598d911b1e7c39bd00

Source dataset

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09434761B2