Dimethyl Sulfoxide → Ethyl-4-(3-methoxyphenyl)-4-methyl-2-oxopentanoate

Participants

Reaction Steps

2019 g (78.47 mmol) of ethyl 4-(3-methoxyphenyl)-2-hydroxy-4-methyl-pentanoate is dissolved in 820 ml of dichloromethane and mixed with 273 ml of dimethyl sulfoxide. After 39.7 g (392.36 mmol) of triethylamine is added, the batch is mixed in portions with 31.2 g (196.18 mmol) of SO3/pyridine complex and then stirred for 16 hours at room temperature. About 400 ml of dichloromethane is drawn off in a rotary evaporator. Then, the reaction mixture is mixed with 312 ml of saturated ammonium chloride solution while being cooled slightly, and it is stirred vigorously for 20 minutes. After 2× extraction with diethyl ether (800 ml each), the combined organic phases are washed with water and brine. The residue that remains after the solvent is spun off is chromatographed on silica gel (mobile solvent ethyl acetate/hexane). 15.59 g (75.3%) of the desired compound is isolated.

Provenance & Evidence