In what organelle would you find acetyl coa formation

The correct answer is: mitochondria

Pyruvates are formed during the glycolysis in the cytosol. Pyruvates are then transported into the mitochondria where they are used for the formation of acetyl CoA. Pyruvate dehydrogenase is an enzyme that oxidizes pyruvate and converts it to Acetyl CoA which is then used in the next step of metabolism, the Krebs cycle (citric acid cycle). So, acetyl CoA  is important for the initiation step of Krebs cycle.