Methyl chloroformate → 1-Ethyl 1-methyl 4,4-dimethoxycyclohexane-1,1-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a −78° C. solution of iPr2NEt (3.95 mL, 27.7 mmol) in THF (50 mL) was added n-BuLi (17.3 mL of a 1.6 M solution in hexanes; 27.7 mmol) was added. After 15 min, ethyl 4,4-dimethoxycyclohexane-carboxylate (4.0 g, 18.50 mmol) was added and the reaction mixture was stirred at −78° C. for 1 h. Methyl chloroformate (2.87 mL, 37.0 mmol) was added and the reaction mixture was warmed to rt. The reaction was quenched with saturated aqueous NH4Cl and extracted with EtOAc (100 mL). The organic layer was dried (Na2SO4) and concentrated in vacuo. The crude oil was chromatographed (SiO2; continuous gradient from 0 to 20% EtOAc:hexanes) to afford the title compound (4.7 g, 93% yield) as a clear oil. 1H NMR (500 MHz, CDCl3) δ 4.21 (q, J=7.1 Hz, 2H), 3.75 (s, 3H), 3.19 (s, 6H), 2.16-2.05 (m, 4H), 1.79-1.69 (m, 4H), 1.27 (t, J=7.1 Hz, 3H).

Provenance & Evidence