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 (By similarity). Involved in the biosynthesis of the dTDP-L-rhamnose which is a component of the critical linker, D-N-acetylglucosamine-L-rhamnose disaccharide, which connects the galactan region of arabinogalactan to peptidoglycan via a phosphodiester linkage (PubMed:16472764). dTDP-alpha-D-glucose = dTDP-4-dehydro-6-deoxy-alpha-D-glucose + H2O Binds 1 NAD(+) per subunit. Carbohydrate biosynthesis; dTDP-L-rhamnose biosynthesis. Homodimer. Belongs to the NAD(P)-dependent epimerase/dehydratase family. dTDP-glucose dehydratase subfamily.