A computer program for calculating the ring-puckering parameters for any five-membered ring from endocyclic torsion angles

A new algorithm and a computer program, CHELAT, for computation of the pseudorotational ring-puckering coordinates on the basis of torsion angles have been developed. The correction factors for nonequilateral geometry can be determined either from a set of experimental torsion angles or from the planar reference-ring geometry.