The first total synthesis of ent-15(RS) 2,3-dinor-5,6-dihydro-8-epi-PGF2 alpha 1 is described using diacetone-D-glucose as starting material. The major urinary metabolite of the isoprostane 8-epi-PGF2 alpha is 2,3-dinor-5,6-dihydro-8-epi-PGF2 alpha, which is a potent lipid peroxidation index to obtain an integrated assessment of oxidative stress in humans. (C) 1998 Elsevier Science Ltd. All rights reserved.