Perforenol, a new polyhalogenated sesquiterpene from

González, Antonio G.; Aguiar, Juan M.; Dárias, José; Gonzalez, Eugenia; Jd, Martín; Martin, Vesely; Pérez, Cirilo; Fayos, J.; Martı́nez-Ripoll, M.

doi:10.1016/s0040-4039(01)95101-9

Cited by 28 publications

(30 citation statements)

References 5 publications

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“…This process, which appears to emphasize bromine, is common in marine organisms and a wide variety of haloterpenoids (approximately 400 are known) are produced. The molecules shown as 11 to 15 were all isolated from red seaweeds (29)(30)(31)(32)(33) and have been selected as examples of this process since, as a consequence of the strategic locations of bromine, each illustrates the very probable involvement of the element in cyclization reactions. The brominated terpenoids 11 to 14 are but a few examples of the many structurally diverse secondary metabolites produced by the prolific red seaweeds of the genus Laurencia (2) (Fig.…”

Section: Secondary Metabolismmentioning

confidence: 99%

See 1 more Smart Citation

Natural Products Chemistry in the Marine Environment

Fenical

1982

Science

184

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Significant differences and numerous similarities exist in the biosynthetic activities of marine and terrestrial plants and animals. While the more primitive marine biota are recognized to possess the common biosynthetic pathways to produce terpenes, acetogenins, aromatic compounds, and alkaloids, in many cases these pathways have been modified in unusual ways. The halogens in sebwater, for example, appear to be fundamentally involved in terpene biosynthesis and in the production of bromine-containinq acetogenins and phenolic compoupds. Marine metabolites have high physiological activities, and these molecules are conceived to function, in part at least, as defensive adaptations In the marine environment.

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Section: Secondary Metabolismmentioning

confidence: 99%

“…11). Palytoxin (30), as isolated from a Hawaiian Palythoa species, is composed of a linear arrangement of 115 carbon atoms with 8 methyl groups and 40 hydroxyl functionalities. Unusual features of palytoxin are two cyclic ketal constellations which are part of 11 ether linkages.…”

Section: Secondary Metabolismmentioning

confidence: 99%

Natural Products Chemistry in the Marine Environment

Fenical

1982

Science

184

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“…3g Despite the interesting bioactivity and compact structure of these molecules, no general strategy for their preparation has been developed, and, to the best of our knowledge, no total synthesis of elatol has been reported in the thirty-three years since its original isolation. 4,5 Structurally, elatol (1) consists of a densely functionalized A ring bearing three stereocenters, including an all-carbon quaternary stereocenter, which is vicinal to a second, non-stereogenic quaternary carbon. Within the B ring is also a fully substituted chlorinated olefin.…”

mentioning

confidence: 99%

The Catalytic Asymmetric Total Synthesis of Elatol

et al. 2007

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The chamigrene subclass of sesquiterpenes, characterized by a spiro[5.5]undecane core, is an ever-growing family of natural products (Figure 1). 1 Well over one hundred members have been isolated thus far, and many of these compounds exhibit a diverse array of biological activity. 1c In particular, elatol (1), 2 one of the most widely studied chamigrenes, displays antibiofouling activity, 3a-b antibacterial activity (including human pathogenic bacteria), 3c-e antifungal activity, 3f and cytotoxicity against HeLa and Hep-2 human carcinoma cell lines. 3g Despite the interesting bioactivity and compact structure of these molecules, no general strategy for their preparation has been developed, and, to the best of our knowledge, no total synthesis of elatol has been reported in the thirty-three years since its original isolation. 4,5Structurally, elatol (1) consists of a densely functionalized A ring bearing three stereocenters, including an all-carbon quaternary stereocenter, which is vicinal to a second, non-stereogenic quaternary carbon. Within the B ring is also a fully substituted chlorinated olefin. We envisioned a strategy toward these challenging motifs based on methodological advances recently reported by our laboratories. Specifically, enantioselective decarboxylative allylation 6 could generate the all-carbon quaternary stereocenter, while ring-closing metathesis (RCM) 7 could be employed to concomitantly provide the tetrasubstituted olefin and the spirocyclic core of 1 (Scheme 1). Importantly, this approach serves as a general platform to access the chamigrene family.We envisioned 1 to ultimately arise from sequential reductive olefin transposition and diastereoselective reduction of α-bromoketone 10. In turn, compound 10 would be obtained from bromination of the enone resulting from 1,2-addition of a methyl anion to spirocycle 11. Intermediate 11 itself could be the product of RCM of α,ω-diene 12. Although generation of a fully substituted chlorinated olefin via RCM has not been previously reported, 8 we anticipated that the improved reactivity of catalyst 22 7 (vide infra) might be sufficient for this transformation. Access to 12 would be possible via enantioselective decarboxylative allylation of an appropriately substituted vinylogous ester derivative (i.e., 13), employing the Pd(0) complex of a phosphinooxazoline (PHOX) ligand. This would constitute a previously unexplored substrate class with this catalyst system. 9 Finally, enol carbonate 13 could be derived from commercially available dimedone (14).Our synthetic efforts began with the condensation of isobutyl alcohol and dimedone (14) to provide known vinylogous ester 15 (Scheme 2). 10 Direct alkylation of vinylogous ester 15 with 4-iodo-2-methyl-1-butene was sluggish; however, a two-step procedure involving conjugate addition to methyl vinyl ketone (MVK) followed by Wittig methylenation afforded olefin (±)-16 in good yield. Selective enolization of vinylogous ester (±)-16 and trapping with chloroformate 17 allowed access to enol carbonate 13 in 7...

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“…The taondiol dimer 2 was also isolated (Gonzalez et al 1971a(Gonzalez et al , 1972a(Gonzalez et al , 1973a.…”

Section: Marine Algaementioning

confidence: 99%