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Rogiolenyne A, B, and C: The First Branched Marine C15 Acetogenins. Isolation from the Red Seaweed Laurencia microcladia or the Sponge Spongia zimocca of II Rogiolo

✍ Scribed by Graziano Guella; Francesco Pietra

Publisher
John Wiley and Sons
Year
1991
Tongue
German
Weight
414 KB
Volume
74
Category
Article
ISSN
0018-019X

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✦ Synopsis

Abstract

It is shown here that the red seaweed Laurencia microcladia, collected off the torrent II Rogiolo, south of Livorno, contains rogiolenyne A (= (−)‐(1__R*,2__S*,3__R*,5__S*,7__S*)‐2‐(bromomethyl)‐5‐[(Z)‐1‐chlorohex‐3‐en‐5‐ynyl]‐3‐ethyl‐4,8‐dioxabicyclo[5.1.0]octane; (−)‐1) while the sponge Spongia zimocca, which grows in the same small area, contains rogiolenyne B (= (−)‐(2__R*3__R*,4__R*,5__R*,7__S__*)‐3‐(bromomethyl)‐5‐chloro‐7‐[(Z)‐1‐chlorohex‐3‐en‐5‐ynyl]‐2‐ethyloxepan‐4‐ol__; (−)‐4a) and its acetate, rogiolenyne C((−)‐4b). These structures, which are based on extensive NMR and MS data and on chemical transformation, are the first examples of branched marine C~15~ acetogenins. Biogenesis of (−)‐1 in L. microcladia is thought to involve C(12) extrusion form a C~15~ linear tetraen‐1‐yne precursor via H^+^‐induced cyclopropane ring closure, followed by Br^+^‐induced cyclopropane ring opening, aided by C–O^−^ attack (Scheme 2). It is also proposed that transfer of (−)‐1 to S. zimocca is followed by epoxide ring opening by Cl^−^ to give (−)‐4a and acetylation to give (−)‐4b.

📜 SIMILAR VOLUMES

Rogiolenyne D, the likely immediate prec
Rogiolenyne D, the likely immediate precursor of rogiolenyne A and B, branched C15 acetogenins isolated from the red seaweed Laurencia microcladia of II Rogiolo. Conformation and absolute configuration in the whole series
✍ Graziano Guella; Ines Mancini; Giuseppe Chiasera; Francesco Pietra 📂 Article 📅 1992 🏛 John Wiley and Sons 🌐 German ⚖ 467 KB

## Abstract It is shown that in the red seaweed __Jaurencia microcladia__, collected in the Mediterranean off the torrent Il Rogiolo, the new branched C~15~ acetogenin rogiolenyne D ( = (+)‐(__2__S,__3__S,__7__R))‐__3__‐__(bromomethyl)‐7‐[(Z)‐1‐chlorohexen‐3‐en‐5‐nyyl)]‐2‐ethyl‐2,3,6,7‐tetrahydroox

On the unusual propensity by the red sea
On the unusual propensity by the red seaweed Laurencia microcladia of II Rogiolo to form C15 oxepanes: Isolation of rogioloxepane A, B, C, and their likely biogenetic acyclic precursor, prerogioloxepane
✍ Graziano Guella; Ines Mancini; Giuseppe Chiasera; Francesco Pietra 📂 Article 📅 1992 🏛 John Wiley and Sons 🌐 German ⚖ 742 KB

## Abstract It is shown here that the red seaweed __Laurencia microcladia__ KÜTZNING, collected in the Mediterranean off the torrent Il rogiolo, contains the C~15~ acetogenin rogioloxepane A ( = (+)‐__(2__R,__7__R__)‐2‐(1‐bromopropyl)‐7‐[(__Z__)‐1‐chlorohex‐3‐en‐5‐ynyl]‐2,3,6,7‐tetrahydrooxepin__;