Rhodomentosones A and B: Two Pairs of Enantiomeric Phloroglucinol Trimers from Rhodomyrtus tomentosa and Their Asymmetric Biomimetic Synthesis

Abstract

Rhodomentosones A and B (1 and 2), two pairs of novel enantiomeric phloroglucinol trimers featuring a unique 6/5/5/6/5/5/6-fused ring system were isolated from Rhodomyrtus tomentosa. Their structures with absolute configurations were elucidated by NMR spectroscopy, X-ray crystallography, and ECD calculation. The bioinspired syntheses of 1 and 2 were achieved in six steps featuring an organocatalytic asymmetric dehydroxylation/Michael addition/Kornblum–DeLaMare rearrangement/ketalization cascade reaction. Compounds 1 and 2 exhibited promising antiviral activities against respiratory syncytial virus (RSV).

Recent advances in the synthesis of natural products containing the phloroglucinol motif

“…Also inspired by Porco's work (Scheme 16), 72 Wang, Ye and Li came out with the asymmetric version of dehydroxylation/Michael addition/Kornblum–DeLaMare rearrangement strategy, which was applied twice on one unit of acylphloroglucinol 86 and two units of syn -endoperoxide 91 (Scheme 19). 77 The stereoselectivity of the reaction was controlled by ( S )- 69 catalyst. Treatment of 86 with syn - 91 in the presence of ( S )- 69 and AlF 3 in toluene yielded a separable mixture of (+)-rhodomyrtosone A ( 92 ) and (−)-rhodomyrtosone G ( 93 ).…”

Xanchryones I−N, Six Unusual Phloroglucinol‐Amino Acid Hybrids from the Leaves of Xanthostemon chrysanthus

“…[1][2][3] Our group has focused on structurally unique and bioactive natural products from Myrtaceae plants. [2][3][4][5][6][7][8][9][10][11][12] In our previous research on the phloroglucinols from Xanthostemon chrysanthus (Myrtaceae), we discovered the first examples of phloroglucinol-amino acid adducts, xanchryones A and B. [12] Meanwhile, xanchryones A and B displayed characteristic even-mass ions in their mass spectra and unique UV absorptions in the range of 200-350 nm.…”

“…Our group has focused on structurally unique and bioactive natural products from Myrtaceae plants [2–12] . In our previous research on the phloroglucinols from Xanthostemon chrysanthus (Myrtaceae), we discovered the first examples of phloroglucinol‐amino acid adducts, xanchryones A and B [12] .…”

Phloroglucinol and Its Derivatives: Antimicrobial Properties toward Microbial Pathogens

“…Copyright 2020 Elsevier Ltd. Image of Rhodomyrtus tomentosa reprinted with permission of ref . Copyright 2021 American Chemical Society.…”