β,β-Carotene-4,4'-diol → Canthaxanthin

Participants

Reaction Steps

1.5 g of sodium bromate dissolved in 20 ml of water is added to 1.5 g of isozeaxanthin dissolved in 250 ml of 1,2-dichloroethane. While stirring, 10 ml of 1,2-dichloroethane in which 30 mg of bromine is dissolved is dripped in over a period of 30 minutes. The pH of the aqueous phase is 5.6. After stirring for 1 hour at room temperature, the phases are separated, the 1,2-dichloroethane is washed with sodium bicarbonate solution and water and dried, and the solvent is distilled off under reduced pressure. 20 ml of methanol is added to the residue and the whole stirred for 10 minutes at 50° C. After cooling, filtration gives 1.36 g (92% of theory) of canthaxanthin.

Provenance & Evidence