4-Hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone , its CAS NO. is 110516-60-4, the synonyms are 2(or 5)-Ethyl-4-hydroxy-5(or 2)-methyl-3(2H)-furanone ; 3(2H)-Furanone, 2(or 5)-ethyl-4-hydroxy-5(or 2)-methyl- .