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Regio- And Diastereoselective Samarium-Mediated Allylic Sulfone Reductions, Cody Schwans

WWU Graduate School Collection

A series of allylic sulfones were synthesized containing a stereodirecting group and chelating element and subjected to samarium diiodide reductions in the presence of a proton donor. The resulting products could be obtained with high regioselectivity (no less than 95:5) and high diastereoselectivity (>10:1) that correlated with the size of the stereodirecting group. A mechanism is proposed that includes loss of the sulfone and formation of a chelated organosamarium intermediate followed by intramolecular protonation by a samarium-bound proton source. In this way, both the regioselectivity and absolute stereochemistry of the resulting products are explained.