In a 100 mL round-bottom flask equipped with a mechanical stirrer, cis-cyclopentane-1,3-diol (3.52 g, 34.44 mmol) was dissolved in 40 mL of acetone. The reaction system was cooled in an ice bath, followed by the slow dropwise addition of a mixed solution consisting of Na2Cr2O7-2H2O (3.49 g, 11.72 mmol), concentrated H2SO4 (2 mL) and H2O (14 mL) over a period of 25 min. The reaction solution showed a greenish-blue color, followed by a slow warming up to room temperature over a period of 15 min. After completion of the reaction, the mixture was filtered through diatomaceous earth and the solid residue was washed with acetone. The filtrate was concentrated under reduced pressure and the resulting crude product was purified by fast column chromatography (eluent: petroleum ether/ethyl acetate, 1:2) to afford 3-hydroxycyclopentan-1-one (2.36 g, 67% yield) as a colorless oil. The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3) and 13C NMR (100 MHz, CDCl3): 1H NMR δ 1.98-2.08 (m, 1H), 2.08-2.32 (m, 3H), 2.32-2.54 (m, 2H), 2.78 (s, 1H), 4.38-4.84 (m, 1H); 13C NMR δ 31.38, 35.40, 47.91, 69.72, 217.80.
