Quercus lactones

from Wikipedia, the free encyclopedia

The Quercus lactones (from Latin quercus "oak") are organic-chemical compounds that u. a. found in alcoholic beverages such as whiskey , sherry and brandy . That is why they are also called “whiskey lactones ”.

Isomerism

They occur in the four stereoisomeric configurations (3 R , 4 R ) or (3 S , 4 S ) (both substituents in the cis position ) and (3 S , 4 R ) or (3 R , 4 S ) (both Substituents in the trans position), d. H. in the form of two pairs of enantiomers , each with a different optical activity (see below in the info box).

The substituents are the methyl group in the 3-position and the n - butyl group on the γ-butyrolactone ring in the 4-position ; According to the more recent nomenclature , these are the 4 and 5 positions.

Only the (3 S , 4 S ) and (3 S , 4 R ) isomers occur in the whiskey aroma .

properties

Depending on the configuration, the compounds have different sensory properties. The two cis isomers have a ten times lower odor threshold than the two trans isomers.

Stereoisomers
Surname (3 R , 4 R ) -quarcus lactone
( cis -isomer)		 (3 S , 4 S ) -quarcus lactone
( cis -isomer)		 (3 S , 4 R ) -quarcus lactone
( trans -isomer)		 (3 R , 4 S ) -quarcus lactone
( trans -isomer)
other names

3-methyl-4-octanolide
β-methyl-γ-octalactone
5-butyl-4-methyldihydro-2 (3 H ) -furanone
5-butyl-4-methyloxolan-2-one ( IUPAC )
5-butyldihydro-4-methylfuran -2 (3 H ) -one

Structural formula Structural formula of (3R, 4R) -cis-3-methyl-4-octanolide Structural formula of (3S, 4S) -cis-3-methyl-4-octanolide Structural formula of (3S, 4R) -cis-3-methyl-4-octanolide Structural formula of (3R, 4S) -cis-3-methyl-4-octanolide
CAS number 121644-12-0 252009-40-8 80041-01-6 105119-22-0
147254-32-8 (mixture of isomers)
PubChem 41285 11094871 11084123 11105597
62900 (mixture of isomers)
Molecular formula C 9 H 16 O 2
Molar mass 156.22 g mol −1
description colorless oil colorless oil colorless oil
odor strong coconut note , sweetish, fresh weak coconut note, earthy, woody, hay-like weak coconut note, weak celery note strong coconut note
taste weak coconut note, creamy reminiscent of coconut, herbaceous Reminiscent of coconut, sweet, creamy, fatty weak, herbaceous
boiling point 124-124 ° C (2266 Pa) 123-125 ° C (2133 Pa)
Refractive index 1.4458 (23 ° C) 1.4402 (23 ° C)
solubility soluble in methanol soluble in methanol and chloroform soluble in methanol and chloroform
Optical activity −76.9 (c = 1.73, methanol, 24 ° C, D ) +81.2 (c = 1.24, methanol, 20 ° C, D ) −82.5 (c = 1.02, methanol, 20 ° C, D )

Emergence

Quercus lactones are created when wine and spirits are stored in oak barrels from the ingredients of the oak wood

Individual evidence

  1. ↑ H.-D. Belitz among other things: Textbook of food chemistry. 6th edition. Springer, Berlin a. Heidelberg 2008, p. 964 ( limited preview in the Google book search).
  2. ↑ a b c W. Ternes: Scientific principles of food preparation. 3. Edition. Behr's Verlag, Hamburg 2008, pp. 313-314, 316 ( limited preview in the Google book search).
  3. ↑ a b c Minoru Ozeki, Daisuke Hashimoto, Kiyoharu Nishide, Tetsuya Kajimoto, Manabu Node: A concise synthetic route to optically active cis- β, γ- disubstituted-γ-butyrolactones via tandem Michael – MPV reaction: new total synthesis of ( - ) - cis-whiskey lactone and ( -) - cis-cognac lactone . In: Tetrahedron: Asymmetry . tape 16 , no. 9 , May 2005, p. 1663-1671 , doi : 10.1016 / j.tetasy.2005.03.017 .
  4. ↑ a b c d e f Xinpeng Jiang, Chunling Fu, Shengming Ma: A Concise Synthesis of (-) - and (+) - Whiskey Lactones . In: European Journal of Organic Chemistry . tape 2010 , no. 4 , February 2010, p. 687-693 , doi : 10.1002 / ejoc.200901058 .
  5. ↑ a b Bin Mao, Koen Geurts, Martín Fañanás-Mastral, Anthoni W. van Zijl, Stephen P. Fletcher, Adriaan J. Minnaard, Ben L. Feringa: Catalytic Enantioselective Synthesis of Naturally Occurring Butenolides via -Allylic Alkylation and Ring Closing Metathesis . In: Organic Letters . tape 13 , no. 5 , March 4, 2011, p. 948-951 , doi : 10.1021 / ol102994q .
  6. ↑ a b c d T. EBATA, K. MATSUMOTO, H. YOSHIKOSHI, K. KOSEKI, H. KAWAKAMI, K. OKANO, H. MATSUSHITA: ChemInform Abstract: Synthesis of (+) - trans-Whiskey Lactone (I), (-) - cis-Whiskey Lactone (II), (+) - Cognac Lactone (III), and (+) - Eldanolide (IV). In: ChemInform . tape 24 , no. 31 , August 3, 1993, p. no – no , doi : 10.1002 / chin.199331159 .
  7. ↑ Erwan Guichoux: Prédiction de la quality des bois de chêne pour l'élevage des vins et des alcools: comparaison des approches physicochimiques, sensorielles et moléculaires. (PDF, 6.3 MB) Thèse présentée à Université de Bordeaux I . Ecole Doctorale Sciences et Environnements, April 6, 2011, p. 222 , accessed April 22, 2012 .

literature