Diethyl Ether → HCID 11535657, compound

Participants

Reaction Steps

To a cooled (−10 to 0° C. bath temperature) solution of 2,3-dihydro-4H-chromen-4-one (8.0 grams, 0.054 mole) and iodomethane (22.8 grams, 10 ml, 0.16 mole) in anhydrous tetrahydrofuran (150 ml) was added portion-wise potassium tertiary butoxide (30 grams, 0.27 mole) under an argon atmosphere. During this process, the temperature was kept between −10 to 0° C. to avoid exothermic reaction. The cooling bath was removed, and the resulting mixture was warmed to room temperature. The mixture was heated at 60° C. for 4 hours, heated at reflux for 1 hour, and cooled to room temperature. Additional iodomethane (16 grams, 7 ml, 0.11 mole) was added, and heating was repeated at 60° C. for 4 hours and at reflux for 1 hour. The cooled solution was poured into a mixture of diethyl ether and water. The organic layer was separated, and the aqueous layer was extracted with diethyl ether. The combined extracts were washed with saturated sodium chloride aqueous solution, dried over sodium sulfate, and concentrated. The residue was chromatographed (silica gel, elution by methylene chloride) to give 5.62 grams (59.1%) of 3,3-dimethyl-2,3-dihydro-4H-chromen-4-one as a clear pale yellow oil.

Provenance & Evidence