A new method is developed to determine the most stable conformations of puckered rings by a comparison of measured and calculated SSCCs (DORCO: determination of ring conformations). The DORCO method extensively uses the ring puckering coordinates to express the properties of a pseudorotating puckered ring. In the case of NMR spin-spin coupling constants (SSCCs) J, this leads to an extension of the Karplus relationship to puckered rings. For five-membered rings with puckering coordinates q and phi, the Karplus relationships adopt the form (n)J(q,phi) or (n)(Jphi). It is shown in this paper that functions (3)J(HCCH)(phi) calculated with coupled perturbed density functional theory for a parent molecule can also be used for derivatives of the parent molecule and help to determine their conformational probability distribution function rho(phi). For this purpose, the DORCO procedure is developed to use functions (n)J(phi) of the parent molecule in connection with measured SSCCs of the substituted compound. DORCO was tested for tetrahydrofuran and two of its derivatives. The most stable conformations were determined by an accuracy of 4% or better.