Water → 1,1-Diethyl 4-oxocyclohexane-1,1-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

The procedure in Sanchez et al., Synth. Comm., 1985, 15, 141 was followed. A mixture of triethyl 4-oxocyclohexane-1,1,3-tricarboxylate, Intermediate 1, (135.2 g, 400 mmol), sodium chloride (70.1 g, 1200 mmol), and H2O (17.30 mL, 960 mmol) in DMSO (530 mL) was stirred at 160° C. (oil bath) under N2 for 3.5 h. The cooled mixture was poured into ice-water (3 L) and extracted with EtOAc (400 mL×3). The combined extracts were washed with brine, dried (Na2SO4) then concentrated to provide the title compound (103.4 g, 397 mmol, 99% yield) as an amber oil. HPLC: 2.04 min (AP 45% at 220 nm). LCMS: m/z 243 (M+H). 1H NMR (500 MHz, CDCl3) δ ppm 1.27 (6H, t, J=7.0 Hz, 9,12-CH3), 2.37 (4H, t, J=6.9 Hz, 3,5-CH2), 2.43 (4H, t, J=6.7 Hz, 2,6-CH2), 4.23 (4H, q, J=7.2 Hz, 8,11-OCH2). 13C NMR (126 MHz, CDCl3) δ ppm 14.1 (9,12-CH3), 31.0 (3,5-CH2), 37.8 (2,6-CH2), 53.6 (4-C), 61.9 (8,11-OCH2), 170.7 (7,10-OC═O), 209.4 (1-C═O).

Provenance & Evidence