Abstract: A non-naturally occurring microbial organism having an isopropanol pathway includes at least one exogenous nucleic acid encoding an isopropanol pathway enzyme. The pathway includes an enzyme selected from a 4-hydroxybutyryl-CoA dehydratase, a crotonase, a 3-hydroxybutyryl-CoA dehydrogenase, an acetoacetyl-CoA synthetase, an acetyl-CoA:acetoacetate-CoA transferase, an acetoacetyl-CoA hydrolase, an acetoacetate decarboxylase, and an acetone reductase. A non-naturally occurring microbial organism having an n-butanol pathway includes at least one exogenous nucleic acid encoding an n-butanol pathway enzyme. Other non-naturally occurring microbial organism have n-butanol or isobutanol pathways. The organisms are cultured to produce isopropanol, n-butanol, or isobutanol.