The absolute configuration of polycephalin C (1) isolated from plasmodia of the slime mold Physarum polycephalum is supposed to be 3''R,4''R as found by comparison of CD spectra of the natural product polycephalin C (1) and CD spectra of synthetic bis-benzoates (-)-4 and (+)-4. An X-ray structure of the corresponding bis-camphanate (+)-3 shows that the exciton chirality method may not be applied on these 1,4-diols in the usual manner.