Catalyzes the dehydration of dTDP-D-glucose to form dTDP-6-deoxy-D-xylo-4-hexulose via a three-step process involving oxidation, dehydration and reduction. dTDP-alpha-D-glucose = dTDP-4-dehydro-6-deoxy-alpha-D-glucose + H2O Binds 1 NAD(+) per subunit. Carbohydrate biosynthesis; dTDP-L-rhamnose biosynthesis. Bacterial outer membrane biogenesis; LPS O-antigen biosynthesis. Homodimer. Belongs to the NAD(P)-dependent epimerase/dehydratase family. dTDP-glucose dehydratase subfamily.