<unk>  is an intermediate in the metabolism of leucine.  It is metabolized to HMG-CoA.
3-Methylglutaconyl CoA
Uridine triacetate
Inositol nicotinate
Uridine diphosphate galactose
Triethanolamine
Crotonyl-coenzyme A
Glutaconyl-CoA
2-Methylbutyryl-CoA