Quinones as Key Intermediates in Natural Products Synthesis. Syntheses of Bioactive Xanthones from Hypericum perforatum

Abstract

Two bioactive xanthones from Hypericum perforatum have been synthesized by direct routes. Benzo[c]xanthone 5 can be prepared from intermediate 4.

O-Annulation Leading to Five-, Six-, and Seven-Membered Cyclic Diaryl Ethers Involving C–H Cleavage

“…55 Daviditin A is used to relax the corpus cavernous smooth muscle, while its Bellidifolin congener is a potent hypoglycemic regulator, improving insulin resistance. 56 Finally, Atroviridin exhibits anti-inflammatory activity and is traditionally used for the treatment of earache (Figure 3). 57 In this regard, research groups have focused on the synthetic methodologies that use biogenetic-type approaches to perform the oxidation of the benzophenone core 63.…”

Theoretical studies to predict the utility of diazo esters in their reactions with 1,4-quinones: experimental validation via a visible light driven metal free process

“…13–18 In addition, they are also present in several active pharmaceutical ingredients (API), in materials with unique electronic and visual properties, as building blocks in synthetic chemistry and in natural and synthetic dyes and pigments. 19–27 The importance of 1,4-quinones has prompted a plethora of methods for the direct functionalization of quinones. 28–69 The different processes that are available include: (i) oxidative radical coupling for alkylations and arylations; (ii) photoinduced radical coupling and synergistic addition/oxidative reactions for alkylations; (iii) transition metal catalysed oxidative Heck type coupling reactions; and (iv) metal catalysed amination, phosphination and sulfenylation.…”

Synthesis, Characterization and Anticancer Efficacy Evaluation of Benzoxanthone Compounds toward Gastric Cancer SGC-7901

“…You et al designed a number of hydroxyxanthone derivatives and found an orally active antitumor agent [ 12 ]. In general, the synthetic methods for benzoxanthone include the displacement of bromides or iodides through nucleophilic aromatic substitution [ 13 ], demethylation with boron tribromide [ 14 ], photooxidative cyclization of 2-styryl-chromones [ 15 , 16 ] and the ultraviolet radiation of benzylidene-1-tetralone [ 17 ]. Synthetic methods for the production of the compounds in Refs.…”

“…Synthetic methods for the production of the compounds in Refs. [ 13 , 14 , 15 , 16 , 17 ] can be seen in the Scheme 1 . However, these methods have some disadvantages, such as harsh reaction conditions, long reaction times and the need for expensive catalysts.…”