Acetic Acid → Chromanol

Participants

Reaction Steps

In a 50 ml four-necked flask were charged 2,3,5-trimethylhydroquinone (5.0 g), zinc chloride (0.8 g), acetic acid (0.35 ml), methyl ethyl ketone (4 ml) and toluene (15 ml) and the mixture was heated. At 100° C., a solution of isoprene (2.5 g) in toluene (5 ml) was added dropwise under reflux over 2 hr. After the dropwise addition, the mixture was refluxed for 4 more hours and cooled to room temperature. The reaction mixture was transferred to a partition funnel, and, after washing 3 times with 50 ml of water, the solvent was evaporated to give 6.5 g of an oily substance.

Provenance & Evidence