Hydrochloric Acid → Ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-oxohexanoate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2.3 ml of oxalyl chloride in 40 ml of methylene chloride cooled at -65° C. is added a solution of 4.45 g of dimethylsulfoxide in 20 ml of methylene chloride over a period of 10 minutes, and the mixture is stirred at -60° C. for 10 minutes. To the mixture is added a solution of 5 g of ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-hydroxyhexanoate in 50 ml of methylene chloride over a period of 10 minutes, and the resulting mixture is stirred at -60° C. for 20 minutes. To the mixture is added 10.3 g of diethylisopropylamine over a period of 10 minutes, and the temperature is raised from -60° C. up to -30° C. To the mixture is added 80 ml of 1N hydrochloric acid, and the mixture is stirred at room temperature. The methylene chloride layer is separated, washed with water, dried and concentrated under reduced pressure. The residue is purified by silicagel column chromatography (hexane:ethyl acetate=4:1 to 2:1), to give 2.6 g of ethyl 6-(1-benzyloxycarbonyl-4-piperidyl)-2-oxohexanoate as an oil.

Provenance & Evidence