Eusiderin

Dihydrobenzofurans eusiderin,160 supposed to be 3-(6-allyl-2,4-di-methoxyphenoxy)-2,3-dihydro-6,7-dimethoxy-2-methylbenzofuran(52). 

Amoldi A, Merlini L (1985) Asymmetric Synthesis of 3-Methyl-2-phenyl-l,4-benzodiox-anes. Absolute Configuration of the Neolignan Eusiderin and Euseridin C and D. J Chem Soc Perkin Trans I 2555... 

Intermolecular oxidative coupling of phenols. Italian chemists have reported a synthesis of the unusual neolignan ( )-eusiderin (4) patterned on a... 

Eupatorium perfoliatum, 3528 Eupatimdin, 3075, 3077 Euphorbiaceae, 176, 756 Euphorbia hirta, 4098 Euphorbinoyl imit, 1983 Eiffopean Food Safety Authority (EFSA), 1135, 1136, 1144, 2446, 2495, 2505-2509 Eiffopean Pharmacopeia (Ph Eur), 3664 Eusiderin, 1558 Eutrophication, 2929 Euxylophora, 720... 

Reexamination of this problem by modem spectrometric techniques invalidated any but the benzodioxane structures 66 15.2b constituting the favoured alternative upon consideration of biosynthetic mechanism 64, 109) and a biogenetically patterned, but not unambiguous, synthesis of the racemate (Chart 24) 109). This postulate was confirmed by a study of the NMR spectral behaviour of eusiderin (15.2b) and eusiderin-B (15.2a) in the presence of Pr(fod)3 33). 

These facts lend significance to lanthanide-induced shift data concerning eusiderin-B (15.2a). Coordination with Pr affects H-7 (A 9.2 ppm) less strongly than H-8 (A 19.2 ppm), and the methoxyl must thus, be located closer to the latter site (as in 15.2a) and not to the former (as in 86a). Structure 15.2a for eusiderin-B was corro-... 

The rm -arrangement of the substituents at C-7 and C-8 of eusiderin was consistent with NMR data (66) and inferred through the NMR spectrum. This showed, in comparison with model neolignan spectra, that Me-8 must be beyond non-bonded interaction range of the Ar-7 substituent (J44). 

Hobbs, J. J., and F. E. King The Chemistry of Extractives from Hardwoods. XXIX. Eusiderin, a Possible By-product of Lignin Synthesis in Eusideroxylon zwageri. J. Chem. Soc. (London) 1960, 4732. 

Dias SMC, Fernandes J B, Maia J G S, Gottlieb O R, Gottlieb H E 1986 The chemistry of Brazilian Lauraceae. LXXVII. Eusiderins and other neolignans from an Aniba species. Phytochemistry 25 213-217... 

Fernandes JB, Nilce Des Ribeiro MN, Gottlieb OR, Gottlieb HE 1980 Chemistry of Brazilian Myristicaceae. Part 13. Eusiderins and 1,3-diarylpropanes from Virola species. Phytochemistry 19 1523-1525... 

Radical coupling followed by nucleophilic attack of hydroxyl on a quinone methide intermediate is postulated as the mechanism of the key step in the syntheses of silybin and eusiderin (eq 10). 1,4-Diketones are produced in the reaction of silyl enol ethers with Ag20 in DMSO (eq 11). ... 

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