Branched nonalactones from some Quercus species

“…Over 200 volatile components of oak wood have been identified, and the aroma and flavour properties of some of these have been characterized. [1][2][3] Free (FVC) and glycosidically bound (BVC) volatile components have been reported in fruits such as grape, passion fruit and raspberry. [4][5][6][7][8] However, there are no reports on glycosidically bound aroma compounds in oak wood.…”

Section: Introductionmentioning

confidence: 99%

Glycosidically bound flavour compounds inQuercus petraea Liebl. wood

Nonier¹,

Vivas²,

Vitry³

2005

Flavour Fragr. J.

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To isolate the bound aroma compounds (BVC fraction) from Quercus petraea Liebl. heartwood, two different methods, XAD-2 adsorption and liquid-liquid extractions, were applied. Only the extraction procedures permitted, for the first time, the isolation and separation of this fraction. The free volatiles were first extracted with pentane:dicholoromethane in a ratio 2:1 (v/v) and the bound compounds with ethyl acetate. The bound aroma was determined directly by trifluoroacetamide (TFA) derivatives analysis, and indirectly by acid hydrolysis release of aglycons. Analyses were achieved, in each case, by GC-MS (EI and CI): several bound components were isolated and different aglycons identified, e.g. whisky lactones (cis + + + + + trans), eugenol, megastigmatrienones, vanillin and syringaldehyde. Each of these can be considered as a source of potential aroma; they have a specific odour in their free form.

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“…In fact, the lactones 4 were not yet the target molecules of our previous e. g. R = Oct (95% ee) ii) e. g. R = Bu, R´ = Me (97% ee) iii) Scheme 1. i) Equivalent to levorotatory aglycon of ranunculin; [7] ii) equivalent to ()-dodecanolide; [8] iii) equivalent to (À)-trans quercus lactone. [9] [*] Prof. Dr. R. Brückner, Dipl.-Chem. C. Harcken, Dipl.-Chem.…”

Section: Introductionmentioning

confidence: 99%

“…[3] Rather, each of them was carried on to a g-chiral butenolide 3 by a b-elimination induced by mesyl chloride/ triethylamine. For R HO ± CH 2 butenolide 3 constitutes the aglycon of ranunculin, [7] for R Oct a precursor of the pheromone ()-dodecanolide (5; [8] available from 3 by catalytic hydrogenation), and for R Bu a precursor of the flavorant (À)-trans quercus lactone (6; [9] available from 3 through the 1,4-addition of Me 2 CuLi).…”

Section: Introductionmentioning

confidence: 99%

Total Syntheses of (−)-Grandinolide and (−)-Sapranthin by the Sharpless Asymmetric Dihydroxylation of Methyltrans-3-Pentenoate: Elucidation of the Stereostructure of (−)-Sapranthin

1998

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Methyl trans-3-pentenoate (7) was converted into the cis-substituted g-lactone 8 in a single step with 78 % ee. The derived enolate dilithio-8 was alkylated trans-selectively with primary iodoalkanes. with 1-iodobutane dilithio-8 afforded, after esterification with isovaleroyl chloride, the epi-blastmycinone 9. Dilithio-8 gave (À)-grandinolide (11) with 1-iodo-19-phenylnonadecane (20). A third trans-selective alkylation of dilithio-8 was undertaken with 16-iodo-1,5-hexadecadiene-7,9-diyne (21). This gave the g-lactone 12, which had the published relative configuration of (À)-sapranthin but different spectroscopic data. When the OH group of lactone 8 was inverted (to hydroxylactone 40) and the derived enolate dilithio-40 alkylated with iodide 21, lactone 41 resulted. Its 1 H and 13 C NMR spectra and the sign and value of optical rotation coincide with the data of natural sapranthin. These findings establish that (À)-sapranthin possesses the relative and absolute configuration of stereoformula 41.

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Branched nonalactones from some Quercus species

Cited by 68 publications

References 0 publications

Characterization of carotenoids and their degradation products in oak wood. Incidence on the flavour of wood

Characterization of carotenoids and their degradation products in oak wood. Incidence on the flavour of wood

Glycosidically bound flavour compounds inQuercus petraea Liebl. wood

Total Syntheses of (−)-Grandinolide and (−)-Sapranthin by the Sharpless Asymmetric Dihydroxylation of Methyltrans-3-Pentenoate: Elucidation of the Stereostructure of (−)-Sapranthin

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