Alternative routes to the acylphloroglucinol rhodomyrtone

Morkunas, Marius; Maier, Martin E.

doi:10.1016/j.tet.2015.10.063

Cited by 14 publications

(6 citation statements)

References 29 publications

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“…In previous work, we had developed three different routes to the tricyclic core of rhodomyrtone. [26,27] For the natural product, we could show that esterification of the phenolic hydroxyl functions on the core (6 a) followed by a Lewis acid induced Fries rearrangement gave rise to 1 in reasonable yield. Xanthene 6 a could be obtained by Knoevenagel condensation of syncarpic acid (3) with isovaleraldehyde followed by condensation of enedione 5 with phloroglucinol (4).…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Rhodomyrtone Analogs Modified at C7

et al. 2023

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We developed a route to rhodomyrtone analogs that feature different acyl groups at C7. Since electrophilic substitution reactions on the aryl part of the rhodomyrtone core led to C5 derivatives, the C5 position was blocked by a chlorine. Subsequent Duff type formylation followed by Grignard addition to the aldehyde group and oxidation gave various phenones. The benzyl protecting groups were removed by hydrogenation or boron tribromide. Some derivatives turned out to be quite active against multiple resistant Staphylococcus aureus strains and a rhodomyrtone resistant mutant (RomR). The chlorine at C5 seems to have a beneficial effect on the antibacterial activity.

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Section: Resultsmentioning

confidence: 99%

Synthesis of Rhodomyrtone Analogs Modified at C7

et al. 2023

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“…However, this reaction only yielded a racemic product 14 . Referenced Maier’s protocol, we then envisioned that (+)- 10 could undergo retro-fries rearrangement to give (+)- 14 , followed by regioselective acylation to generate chiral rhodomyrtone ( 11 ). Unfortunately, when we treated dimer (+)- 10 with p -TsOH in toluene at high temperatures, (+)- 10 unexpectedly underwent racemization to afford racemic 14 .…”

Section: Resultsmentioning

confidence: 99%

Discovery and Biomimetic Synthesis of a Polycyclic Polymethylated Phloroglucinol Collection from Rhodomyrtus tomentosa

et al. 2022

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Inspired by a previously reported biomimetic synthesis study, four new naturally occurring phloroglucinol trimers 1–4 with unusual 6/5/5/6/6/6-fused hexacyclic ring systems, along with two known analogues (5 and 6) and two known biogenetically related dimers (10 and 11), were isolated from Rhodomyrtus tomentosa. Their structures and absolute configurations were unambiguously elucidated by spectroscopic analysis, X-ray diffraction, and electronic circular dichroism calculation. By mimicking two potentially alternative biosynthetic pathways, the first asymmetric syntheses of 1–4 and the racemic syntheses of 5 and 6 were achieved in only five to six steps without the need for protecting groups. Furthermore, phloroglucinol dimers 10 and 11 exhibited significant in vitro antiviral activity against the respiratory syncytial virus.

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“…Structural analysis revealed that Rom belongs to the acylphloroglucinol class ( 1 ). The elaboration of a chemical synthesis route of Rom and thus the production of larger quantities enabled the study of the mode of action ( 8 , 9 ).…”

Section: Introductionmentioning

confidence: 99%