The synthesis and characterization of 5-(acetoxymethyl)-5-ethyl-1,3-dioxacyclohexane as well as the determination of its dipole moment are described. The critical interpretation of the polarity of this compound by using molecular dynamics (MD) suggests that the trajectories in which the CH3COOCH2 residue is attached in the equatorial position to the C-(5) bond of the 1,3-dioxacyclohexane ring exhibit dipole moments which are noticeably smaller than those produced with the residue in the axial position. By calculating the time spent by the residue in each conformation at several temperatures, one finds that the activation energy associated with the chair-to-chair transition is ca. 8.0 kcal mol(-1), and the time spent by the ester residue in the axial and equatorial conformations is nearly identical. Hence the mean-square dipole moment at 30 degrees C was obtained by averaging the values of this quantity for the equatorial (2.12 D-2) and axial (15.21 D-2) trajectories, obtaining [mu(2)] = 8.7 D-2, in good agreement with the experimental result (9.1 D-2).