Syntheses of Macrocyclic Bis(bibenzyl) Compounds Derived from Perrottetin E

Abstract

Macrocyclic bis(bibenzyl) compounds are natural products from liverworts and are of growing interest due to recent reports on new isolated compounds and on their remarkable biological activities. We report here on a flexible and general approach to the total set of nine bis(bibenzyl) compounds of the riccardin and plagiochin type derived from perrottetin E. The structures were confirmed through their spectroscopic data, which were compared carefully with those for the isolated products to exclude any errors in arene connection and substitution pattern.

Unified Syntheses of Cavicularin and Riccardin C: Addressing the Synthesis of an Arene Adopting a Boat Configuration

“…Thus, treatment of the product mixture with boron tribromide provided synthetic samples of cavicularin (5) and riccardin C (4) in 32 and 63 % yield, respectively, each displaying spectral characteristics identical to those reported for the natural products. [3,4,10,11] It is interesting to note that for riccardin C (4) [3,4,10,11] In CDCl 3 at 25 8C the 1 H NMR spectrum shows significant broadening of all ArCH 2 signals and those of the A ring. Consequently, the Scheme 1.…”

“…As with trans-stilbene 29, an X-ray crystal structure of compound 43 revealed a boat configuration in arene A akin to that in cavicularin itself. [10] Furthermore, its trans-stilbene displays a torsional angle of 1678 across the double bond, which in turn has bond angles ranging from 115-1298 ( Figure 3). …”

“…[8] Recently, riccardin C (4) gained prominence as a partial liver X receptor (LXR) a agonist and LXRb antagonist, [3,9,10] these playing a critical role in maintaining lipid homeostasis through the regulation of several genes involved in the efflux, transport and excretion of cholesterol.…”

An iterative in silico and modular synthetic approach to aqueous soluble tercyclic α-helix mimetics

“…The mixture was allowed to warm to room temperature and stirred for 2 h before it was washed with 1 M HCl (4 × 15 mL), the organic layer dried over MgSO 4 and the volatiles removed in vacuo to afford the title compound 13 as a clear oil (1.17 g, 63%) with spectral data concordant with the literature. 40 Ethyl 2-methoxy-4-(4-methylpyridin-3-yl)benzoate (18). A mixture of ethyl 2-methoxy-4-(((trifluoromethyl)sulfonyl)oxy)-benzoate (12) (0.23 g, 0.71 mmol), Na 2 CO 3 (0.23 g, 2.14 mmol), (4-methylpyridin-3-yl)boronic acid (0.12 g, 0.86 mmol) and tetrakis(triphenylphosphine)palladium (41 mg, 36 µmol) in degassed dioxane-H 2 O (3 : 1, 5 mL) was microwave irradiated at 130°C for 20 min.…”

Total synthesis of plagiochin G and derivatives as potential cancer chemopreventive agents

“…5-7 These compounds are divided into four distinct structural types ( I − IV , Figure 1), 8 each containing four aromatic rings (labelled A − D ) and two ethylene bridges, and originate biosynthetically from bibenzyl lunularin or its precursor lunularin acid. 7, 9 The plagiochin family of type II macrocyclic bisbibenzyls includes natural plagiochins A−D isolated from the liverwort Plagiochila acanthophylla by Hashimoto et al 10 and plagiochins E−H synthesized by Speicher et al 11 …”