Catalyzes the dehydration of dTDP-D-glucose to form dTDP-4-dehydro-6-deoxy-D-glucose via a three-step process involving oxidation, dehydration and reduction. This reaction is a step in the biosynthesis of D-fucofuranose, a component of E.coli O52 O antigen. dTDP-alpha-D-glucose = dTDP-4-dehydro-6-deoxy-alpha-D-glucose + H2O Binds 1 NAD(+) per subunit. Bacterial outer membrane biogenesis; LPS O-antigen biosynthesis. Belongs to the NAD(P)-dependent epimerase/dehydratase family. dTDP-glucose dehydratase subfamily.