Transformation of Prostaglandin D to 11-Dehydro Thromboxane B by Baeyer-Villiger Oxidation.

Prostaglandin D is one of five chief prostanoids formed in the cyclooxygenase pathway of arachidonic acid oxidation. Except for a single oxygen atom, PGD is structurally identical to 11-dehydro thromboxane B (11d-TxB ), a urinary metabolite of the pro-aggregatory platelet activator, thromboxane A . The close structural relationship suggested that one might be transformed to the other. Accordingly, we tested whether the cyclopentanone of PGD can be expanded to the δ-lactone of 11d-TxB in a Baeyer-Villiger oxidation. Oxidation of PGD with two standard oxidants showed that 11d-TxB was formed only with H O but not with peracetic acid. Byproducts of the H O -mediated oxidation were hydroperoxide derivatives and isomers of PGD . Chemical oxidation of PGD to 11d-TxB may be a model for an equivalent enzymatic transformation, suggesting a possible link in the metabolism of PGD and thromboxane A .