CDP-alpha-D-abequose + NADP(+) = CDP-4-dehydro-3,6-dideoxy-alpha-D-glucose + H(+) + NADPH Bacterial outer membrane biogenesis; LPS O-antigen biosynthesis. The functional difference between abequose synthase and paratose synthase lies in the side of the pyranose ring from which the keto group on carbon 4 is attacked in the reduction of CDP-4-keto-3,6-dideoxy-D-glucose. Belongs to the NAD(P)-dependent epimerase/dehydratase family.