2 molecules of acetyl-CoA are condensed to acetoacetyl-CoA by acetyl-CoA acetyltransferase (thiolase)
Condensation of acetoacetyl-CoA with the third acetyl-CoA to form b-hydroxyl-b-methylglutaryl-CoA (HMG-CoA) by HMG-CoA synthase
HMG-CoA is degraded to acetoacetate and acetyl CoA by HMG-CoA lyase