Oxidative Dimerization of 1Н-Benzo[f]chromenes: Synthesis of Benzannulated Analogues of Spirobiflavonoids Welwitschins E and F

A new oxidative transformation of 1H-benzo[f]chromenes into spirodimers under the action of selenium dioxide was discovered, leading to spirodimers, which are dibenzannulated analogues of naturally occurring welwitschins E and F. In the reaction, both MnO2 and I2O5 can also be used as an oxidant. The protocol has advantages of mild reaction conditions and simple operation. At the same time, oxidation of 1H-benzo[f]chromenes with (diacetoxyiodo)benzene is accompanied by the formation of 3,3′-bibenzo[f]chromene as a dimer of a different structure. It was also found that 4H-chromenes under the action of various oxidants are cleaved to give chalcone.

Oxidative Electro-organic Synthesis of Dimeric Hexahydropyrrolo-[2,3-b]indole Alkaloids Involving PCET: Total Synthesis of (±)-Folicanthine

An efficient electrochemical strategy has been developed for the total synthesis of dimeric hexahydropyrrolo[2,3-b]indole alkaloids. In particular, oxidative dimerization of 3-alkyl 2-oxindoles was developed for this study. A detailed CV...

Synthesis of Divanillin in the Presence of Water Extract and Juice of Horseradish Root

The divanillin synthesis by oxidative dimerization of vanillin in the presence of juice and water extracts of horseradish root (Armorácia rusticána), a more available and cheaper catalyst as compared with horseradish reactive peroxidase (HRP) was studied. The divanillin yield exceeds 90 mol. % based on loaded vanillin. The peroxidase activity in juice and water extracts of horseradish root was estimated