反应详情

Acetal 2 (1.01 g, 5.54 mmol) was stirred in a mixture of 2N hydrochloric acid (10 mL) and acetone (10 mL) for 24 hours. After this time, tlc showed complete consumption of the starting acetal. Saturated sodium carbonate solution (20 mL) was added, and the mixture was extracted with ether (3×25 mL). The combined ether fractions were washed with brine, dried (MgSO4), and the solvent was evaporated under reduced pressure. The residue was chromatographed (SiO2, pentane/ether, 95:5) to give the ketone 3 (0.75 g, 97%) as a colorless oil; Rf (heptane/ethyl acetate, 8:2) 0.42; νmax(film)/cm−1 1743 (C═O); δH (400 MHz; CDCl3): 2.37–2.28 (2H, m), 2.20 (2H, dd, J=18.5, 7.5), 2.12 (2H, dd, J=18.7, 6.3), 1.65–1.24 (10H, m).

1. customconsumption of the starting acetal
2. additionSaturated sodium carbonate solution (20 mL) was added
3. extractionthe mixture was extracted with ether (3×25 mL)
4. washThe combined ether fractions were washed with brine
5. dry with materialdried (MgSO4)
6. customthe solvent was evaporated under reduced pressure
7. customThe residue was chromatographed (SiO2, pentane/ether, 95:5)