The isolated-pentagon-rule (IPR) D-5h-C-70 fullerene is least susceptible to skeletal transformations in comparison with higher fullerenes and even C-60. A cage transformation in IPR C-70 via a one-step Stone-Wales rearrangement was accomplished by high-temperature (440 degrees C) ampule chlorination with SbCl5. Subsequent dechlorination at 450 degrees C, followed by high-performance liquid chromatography separation, allowed the isolation of non-IPR C70Cl6 and C70Cl8. X-ray diffraction study revealed the presence of an unprecedented C-70 carbon cage, possessing two pairs of fused pentagons and the chlorination patterns located on one cage hemisphere. A high energetic and thermal stability of both non-IPR chlorides was also confirmed by theoretical calculations of formation energies. Pathways of skeletal transformations of IPR C-70 in comparison with those in C-60 are discussed.