Hydrochloric Acid → 3-Benzylcyclopent-2-en-1-one

Temperature

-30 °C

To a −78° C. solution of benzyl magnesium chloride (14.3 mL, 28.5 mmol, 1.2 eq, 2 M solution in THF) in ether (50 mL) was slowly added 3-ethoxycyclopent-2-enone (2.84 mL, 23.8 mmol, 1 eq.). The reaction mixture was warmed up to −30° C. over 1 hour. At this point, a 1 M solution of HCl was added to the reaction mixture until the pH was adjusted to 1 as indicated by litmus paper. The solution was warmed up to room temperature and the layers were separated. The aqueous phase was extracted with 40 mL of Et2O (3×) and the combined organic layers were washed with 100 mL of brine (1×), dried over anhydrous MgSO4 and concentrated in vacuo. The residual oil was purified by flash chromatography (25% EtOAc/hexanes) to give (3.1 g, 76% yield) of the title compound as a colorless oil.

1. customTo a −78° C.
2. temperatureThe solution was warmed up to room temperature
3. customthe layers were separated
4. extractionThe aqueous phase was extracted with 40 mL of Et2O (3×)
5. washthe combined organic layers were washed with 100 mL of brine (1×)
6. dry with materialdried over anhydrous MgSO4
7. concentrationconcentrated in vacuo
8. customThe residual oil was purified by flash chromatography (25% EtOAc/hexanes)

ORD record

ord-8c35cb07297d4ff5aa1fb715b9bcb4da

Source dataset

uspto-grants-2008_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07323604B2