Typical fatty acids cannot be converted to glucose because

Typical fatty acids cannot be converted to glucose because their catabolic pathways produce acetyl-CoA. It is a 2 carbon molecule, that is why it cannot be formed back into glucose. End product of glycolysis is a pyruvate molecule. Then, it is converted into acetyl-CoA by an enzyme. There are no available enzyme to be able to reverse this process and Acetyl CoA cannot participate in gluconeogenesis.