Synthesis of the enediol isofurans, endogenous oxidation products of arachidonic acid.

Isofurans (IsoF's) are a new class of human arachidonic acid oxidation products. They are produced in vivo by a free radical mechanism, independent of the cyclooxygenase enzymes. These new compounds are available from natural sources only in microgram quantities as mixtures. The enantioselective preparation of two enediol isofurans, 15-epi-ent-SC-Delta13-8-IsoF and ent-SC-Delta13-8-IsoF, is described. A key transformation in the synthesis is the selective cascade cyclization of a diol epoxide benzenesulfonate to give the substituted tetrahydrofuran skeleton of the isofurans. This synthesis will make these metabolites available for physiological evaluation.