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Wine lactone

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Structural formula
Strukturformel von Weinlacton
General
Name Wine lactone
Other names

(3S,3aS,7aR)-3,6-Dimethyl-3a,4,5,7a-tetrahydro-3H-1-benzofuran-2-on

Sum formula C10H14O2
External identifiers/databases
CAS number 182699-77-0
PubChem 6427076
Wikidata Q424963
Features
Molar mass 166.22 g-mol-1
State of aggregation

synced and corrected by elderman — – for —

Melting point

50-51 °C (3S,3aS,7aR)[1]
58-59 °C (3R,3aS,7aR)[1]
59-60 °C (3S,3aR,7aR)[1]
49-51 °C (3R,3aR,7aS)[1]

Safety instructions
GHS hazardous substance labeling
no classification available[2]
SI units are used wherever possible and customary. Unless otherwise stated, the data given are valid for standard conditions.

Wine lactone is a chemical compound found in wine belonging to the group of bicyclic lactones. It has an intensely sweet and coconut-like odor,[3] which is still perceptible even in great dilution.

Isomeric

Structural formula with numbered positions and stereocenters marked with an asterisk in each position

Due to the structural design of the molecule with three stereocentres, there are four pairs of enantiomers or eight diastereomers.

The actual wine lactone is present in the (3S,3aS,7aR) configuration and has the lowest odor threshold of all isomers, being perceptible at concentrations as low as 0.00001 to 0.00004 nanograms per liter of air.

The very different odor thresholds of the eight isomers in air were determined as follows:

Structural formula Configuration according to CIP convention CAS number Odour threshold [ng/l][4]
(3S,3aS,7aS)-Isomer (3S,3aS,7aS) 182699-81-6 0,007–0,014
(3R,3aR,7aR)-Isomer (3R,3aR,7aR) 14–28
(3R,3aR,7aS)-Isomer (3R,3aR,7aS) 182699-78-1 > 1000 (odourless)
(3R,3aS,7aS)-Isomer (3R,3aS,7aS) 182699-83-8 8–16
(3S,3aR,7aR)-Isomer (3S,3aR,7aR) 0,05–0,2
(3S,3aS,7aR)-Isomer (3S,3aS,7aR) 182699-77-0 0,00001–0,00004
(3S,3aR,7aS)-Isomer (3S,3aR,7aS) 182699-80-5 80–160
(3R,3aS,7aR)-Isomer (3R,3aS,7aR) 182699-79-2 > 1000 (odourless)

The racemate carries the CAS number 78168-36-2.
The isomers can be separated by gas chromatography on a chiral stationary phase.[4]

Display

(3S,3aS,7aR)-wine lactone and (3R,3aS,7aR)-wine lactone can be represented from (1R)-trans-isolimones.[5]

Synthese von Iodoweinlacton

After a multi-step reaction, a mixture of (3S,3aS,6R,7R,7aR)-7-iodo-3,6-dimethylhexahydrobenzofuran-2(3H)-one and (3R,3aS,6R,7R,7aR)-7-iodo-3,6-dimethylhexahydrobenzofuran-2(3H)-one is obtained, which can be separated chromatographically. The desired isomer can then be reacted with diazabicycloundecene to give the corresponding wine lactone.

Synthese von Weinlacton

Individual references

  1. a b c d Stefano Serra, Claudio Fuganti: Natural p-Menthene Monoterpenes: Synthesis of the Enantiomeric Forms of Wine Lactone, Epi-wine Lactone, Dill Ether, and Epi-dill Ether Starting from a Common Intermediate. In: Helvetica Chimica Acta. Vol. 87, No. 8, August 2004, ISSN 0018-019X, pp.2100-2109 , doi:10.1002/hlca.200490189.
  2. This substance has either not yet been classified with regard to its hazard or a reliable and citable source on this has not yet been found.
  3. H. Guth: Determination of the configuration of wine lactone. In: Helvetica Chimica Acta. Vol. 79, Issue 6, 1996, pp. 1559-1571; doi:10.1002/hlca.19960790606.
  4. a b H.-D. Belitz et al: Textbook of food chemistry. 5. Edition. Springer, Berlin et al. 2001, pp. 343-345.(restricted preview in Google Book Search).
  5. Subhash P. Chavan, Rajendra K. Kharul, Anil K. Sharma, Sambhaji P. Chavan: An efficient and simple synthesis of(-)-wine lactone. In: Tetrahedron: Asymmetry. Vol. 12, No. 21, November 2001, ISSN 0957-4166, pp.2985-2988 , doi:10.1016/S0957-4166(01)00511-0.