Structures and energies of the more stable conformations of CmH2m+1OCH2CH2OH (C(m)E(1), m = 1-4) have been determined by gradient geometry refinement at ab initio level. For m = 3 (C(3)E(1)) and m = 4 (C(4)E(1)), the results show that attractive CH-O intramolecular interactions associated with the formation of five-membered rings in the alkylic fragments of these molecules lead to the stabilization of gauche arrangements in the CC-CO axes. Since these CH-O interactions compete, in energy terms, with conformational effects, they are found to have important structural consequences. In addition, the formation of five-membered rings closed by CH-O and OH-O contacts gives rise to vibrational couplings in the C(H-2)($) under bar tO ($) under bar tC(H-2) moieties and to conformationally sensitive vibrations.