Trans-3-Methyl-4-octanolide

trans-3-Methyl-4-octanolide

Names
IUPAC name (4R,5S)-5-butyl-4-methyldihydrofuran-2(3H)-one
Identifiers
CAS Number	(4R,5S): 105119-22-0 (-) N (4S,5R): 80041-01-6 (+) N
3D model (JSmol)	(4R,5S): Interactive image (4S,5R): Interactive image
ChemSpider	(4R,5S): 9280733 Y (4S,5R): 9259269
PubChem CID	(4R,5S): 11105597 (4S,5R): 11084123
UNII	(4R,5S): 9OQS29SV9M (4S,5R): 7A29T3GS95
CompTox Dashboard (EPA)	(4S,5R): DTXSID801017484
InChI InChI=1S/C9H16O2/c1-3-4-5-8-7(2)6-9(10)11-8/h7-8H,3-6H2,1-2H3/t7-,8+/m1/s1 Y (4R,5S): InChI=1S/C9H16O2/c1-3-4-5-8-7(2)6-9(10)11-8/h7-8H,3-6H2,1-2H3/t7-,8+/m0/s1
SMILES (4R,5S): O=C1O[C@@H](CCCC)[C@@H](C1)C (4S,5R): CCCC[C@H]1OC(=O)C[C@@H]1C
Properties
Chemical formula	C9H16O2
Molar mass	156.222
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

trans-3-Methyl-4-octanolide, also called trans-β-methyl-γ-octalactone is a chemical compound of the lactone family with formula C
₉H
₁₆O
₂. It exists in two stereoisomers: (3R,4S) and (3S,4R).

The (3S,4R) form is found in whiskey and other alcoholic beverages that have been aged in oak barrels, together with the more important cis isomer.^[1][2] It has a coconut, celery or fresh wood aroma, that can be detected by humans at the concentration of 20 μg/L in air.^[3] A mixture of the cis and trans isomers is repellent for mosquitos and flies.^[4]

The (3S,4R) isomer is extracted by the alcoholic beverage from some precursor substances in the oak wood.^[5] It can be synthesized in various ways.^[3][6][7]