Stereochemistry of Sphinxolides and Reidispongiolides. Asymmetric Synthesis of the C17−C22 Fragment of Reidispongiolide A

Five fragments, 2a−4b, embedding all the stereogenic centers of reidispongiolide A (1), have been prepared by a controlled ozonolysis of the natural compound. The absolute stereochemistry of the asymmetric centers of fragment 3, corresponding to the C17−C22 portion of reidispongiolide A, was determined by enantioselective synthesis and application of the advanced Mosher method.

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