Sulfuric Acid → Spiro(4.5)dec-6-ene-8-one

Temperature

45 °C

To a solution of cyclopentanecarbaldehyde (Aldrich) (0.82 g, 8.36 mmol) in dry toluene (10 mL), methyl vinyl ketone (Alfa Aesar) (0.684 mL, 8.36 mmol) was added followed by a catalytic amount of concentrated H2SO4 (0.045 mL, 0.836 mmol). The mixture was heated at 45° C. for 1.5 hours, then refluxed for 1 hour using a Dean-Stark trap. The reaction mixture was cooled to room temperature and further methyl vinyl ketone (Alfa Aesar) (0.684 mL, 8.36 mmol) was added. The reaction mixture was heated at reflux for 1 hour, allowed to cool to room temperature and treated with an aqueous 1M NaHCO3 (30 mL) solution. The aqueous was extracted with toluene and the combined organic extracts were washed with brine, dried over MgSO4, filtered and concentrated under reduced pressure. The crude material was adsorbed onto silica and purification by chromatography eluting with 0-20% EtOAc in iso-hexane afforded the title compound;

1. temperaturerefluxed for 1 hour
2. temperatureThe reaction mixture was cooled to room temperature
3. temperatureThe reaction mixture was heated
4. temperatureat reflux for 1 hour
5. temperatureto cool to room temperature
6. extractionThe aqueous was extracted with toluene
7. washthe combined organic extracts were washed with brine
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customThe crude material was adsorbed onto silica and purification by chromatography
12. washeluting with 0-20% EtOAc in iso-hexane

ORD record

ord-8920412465434c25af786424ec00ddb1

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09403810B2