-2-deoxyribose . D -2-Deoxyribose is a precursor to the nucleic acid DNA . 2-Deoxyribose is an aldopentose , that is, a monosaccharide with five carbon atom s and having an aldehyde functional group . In aqueous solution, deoxyribose primarily exists as a mixture of three structures: the linear form H-(C=O)-(CH 2