A simplified synthesis of the diastereomers of Levuglandin E-2

We report a synthesis of Levuglandin E-2, as a mixture of easily separable diastereomers (15-E-2-isoketals). The key feature is the protection of its reactive aldehyde as dimethyl acetal, which is introduced with 2,2-dimethoxyethanal and removed in minutes with Montmorillonite K-10. The synthesis could be modified to the preparation of 15-E-2-isoketals with stable isotopes or with radiolabels.