2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → Isoflavone

Participants

Reaction Steps

Using the general procedure of hydroboration-oxidation, compound 1 was converted into a chroman-4-ol (compound 4) at a yield of 60%. Compound 4 was treated with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in refluxing 1,4-dioxane to undergo oxidation-dehydrogenation to give an isoflavone (compound 5) at a yield of 78%. After the deprotection of compound 5 with AlCl3/EtSH, daidzein (compound 6a) was produced at a yield of 92%. On the other hand, compound 5 could be selectively debenzylated with Pearlman's reagent to give formononetin (compound 6b) at a yield of 94%,

Provenance & Evidence