Syntheses of Naturally Occurring Terphenyls and Related Compounds

Abstract

Naturally occurring terphenyls and related compounds such as terferol and its corresponding quinone and phlebiarubrone were synthesized from 2,5-diphenyl-1,4-benzoquinone. According to the proposed biosynthetic pathway, chemical conversion of phlebiarubrone to ustalic acid, a toxic compound isolated from the poisonous mushroom, Tricholoma ustale, was examined to find a low-yield conversion to the ustalic acid dimethyl ester.

Studies on Naturalp-Terphenyls: Total Syntheses of Vialinin A and Terrestrin B

“…For example, 32 underwent hydrolysis under acidic conditions to give 4 0 ,4 00 -dihydroxy-phlebiarubrone (33), have been isolated from a culture of Punctularia atropurpurascens. [38][39][40] The spectral and physical properties of 33 were identical to those of reported 33. On the other hand, reduction of 32 gave corresponding catechol 34 which was immediately acylated to give 35.…”

“…Merck precoated silica gel 60 F 254 plates of 0.25 mm thickness were used for analytical thin-layer chromatography. The solvent extracts were dried with magnesium sulfate, and the solutions were evaporated under reduced pressure at [35][36][37][38][39][40] C.…”

Electrochemical dimerization of 4-methylesculetin: Synthesis and kinetic study of a highly-oxygenated dimer

“…They can be oxidized to relative o-quinone chemically or electrochemically due to their redox activity [15]. Also, it is demonstrated in comparison with simple catechols the highly-oxygenated catechols exhibit interesting biological activities [16][17][18]. So, the development of a simple synthetic route for the synthesis of highly-oxygenated catechol from readily available reagents is one of the major tasks in this paper.…”

Structural Study on a Naturally Occurring Terphenyl Quinone

“…In the same year, we reported a synthesis of proposed compound 1, although its NMR spectra were not identical to the reported data. 5) We next proposed that o-terphenyl o-quinone 2 would be another possible structure which could also explain the NOE data (from methoxy protons to the quinone proton) reported by Singh and co-workers. In order to compare their NMR spectra, we embarked on the synthesis of 2, although an o-terphenyl compound has not been isolated from natural sources.…”