[O:1]=[C:2]1[CH2:6][CH2:5][C:4]([CH:11]([CH3:13])[CH3:12])([C:7]([O:9]C)=[O:8])[CH2:3]1>O1CCOCC1.Cl>[O:1]=[C:2]1[CH2:6][CH2:5][C:4]([CH:11]([CH3:13])[CH3:12])([C:7]([OH:9])=[O:8])[CH2:3]1A solution of methyl 3-oxo-1-isopropylcyclopentanecarboxylate (27 g, 146.6 mmol) in dioxane (300 mL) and conc HCl (100 mL) was heated to reflux overnight. The crude product was extracted into diethyl ether (4×200 mL) and the combined organic extracts were washed with an aqueous solution of sodium hydroxide (5N, 2×150 mL). The combined aqueous extracts were cooled to 0° C. and acidified with conc HCl. The product was extracted with ether (3×200 mL), dried with magnesium sulfate and the solvent was evaporated in vacuo. The weight of the product was 20 g (98%). 1H NMR (500 MHz, CDCl3): 2.81 (d, J=8.54 Hz, 1H), 2.48 (m, 1H), 2.32 (m, 2H), 2.15 (d, J=18.53 Hz, 1H), 2.08 (m, 1H), 1.95 (m, 1H), 1.03 (d, J=6.86 Hz, 3H), 0.96 (d, J=6.87 Hz, 1H).
Wird geladen…