Dimethyl Sulfate → 6-ETHYL-4-METHOXY-2-PYRANONE

Participants

Reaction Steps

The following is based on the procedure disclosed in Deshpande, V. H. et al. Indian Journal of Chemistry, 35, pp. 790-793 (1996). Compound V (57.65 g, 411 mmol) was placed in an oven dried 2000 mL three-neck flask and dissolved in dry acetone (1500 ml). To this solution was added potassium carbonate (74 g, 540 mmoles) and dimethylsulfate (51 ml, 540 mmoles). The flask was equipped with a water condenser and mechanical stirrer. The mixture was heated to reflux for 3.5 hours. Analysis by LCMS showed reaction to be complete. Therefore the reaction was cooled to room temperature and the solids removed by filtration. The solvent of the filtrate was removed by rotary evaporation. The yellow oily residue left behind was purified by silica gel chromatography eluting with a gradient of 10% to 50% ethyl acetate in hexanes. The appropriate fractions were collected and concentrated by rotary evaporation to yield compound W (40.55 g, 61%) as a yellow solid. 1H NMR CDCl3 δ: 5.78 (s, 1H), 5.42 (s, 1H), 3.80 (s, 3H), 2.51 (q, 2H, J=8.0 Hz), 1.22 (t, 3H, J=8.0 Hz). ESMS m/z: 155 [M+H+].

Provenance & Evidence