Beta oxidation of butanoyl-CoA to acetyl-CoA

The seventh and final pass through the beta-oxidation spiral picks up where the last left off with the saturated fatty acid butanoyl-CoA and at the third step produces acetoacetyl-CoA, which can be used to generate 2 acetyl-CoA molecules or can be turned toward the synthesis of ketone bodies pathway. Four enzymatic steps are required starting with SCAD CoA dehydrogenase (Short Chain) activity, followed by the enoyl-CoA hydratase activity of crotonase, the 3-hydroxyacyl-CoA dehydrogenase activity of the short chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD). The final enzymatic step, creating two acetyl-CoA molecules requires a specific ketoacyl-CoA thiolase, Acetoacetyl-CoA thiolase.

Summary from Reactome (R-HSA-77352), read 2026-09-23.