1,4-Dioxaspiro[4.5]decan-8-one → HCID 19705234, compound

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Reaction Steps

The Grignard reagent of 2-bromo-2-(3-chlorophenyl)propane is prepared by adding dropwise a solution of 9.3 grams (0.040 mole) of 2-bromo-2-(3-chlorophenyl)propane in 45 mL of dry tetrahydrofuran to 1.1 grams (0.044 mole) of magnesium turnings in 25 mL of refluxing tetrahydrofuran. Upon completion of addition, the Grignard reagent is stirred at reflux for one hour. The reaction mixture is then cooled in an ice-water bath, and a solution of 6.2 grams (0.040 mole) of 1,4-cyclohexanedione mono-ethylene ketal in about 25 mL of tetrahydrofuran is added dropwise. Upon completion of addition, the reaction mixture is allowed to warm to ambient temperature where it is stirred for about 18 hours. After this time the reaction is quenched by the addition of 100 mL of aqueous 10% hydrochloric acid. The reaction mixture is stirred for 10 minutes and then is extracted with two 50 mL portions of diethyl ether. The combined extracts are washed with 10 mL of water and then are dried with magnesium sulfate. The mixture is filtered and concentrated under reduced pressure, yielding 1-[2-(3-chlorophenyl)propan-2-yl]-1-cyclohexen-4-one.

Provenance & Evidence