Law Student

University of Maryland, College Park (College Park, MD)

Silylene mediated synthesis of α-hydroxy acids and application to the synthesis of ferupennin F

Treatment of allylic α-keto esters with silylene results in the diastereoselective formation of α-hydroxy acids. This transformation is postulated to occur through a silacarbonyl ylide intermediate that undergoes a 6π-electrocyclization and tandem Ireland–Claisen rearrangement. A wide variety of substitution patterns on the α-keto esters are tolerated by the transformation, including several examples of sterically demanding substrates. Chiral α-keto esters afford chiral α-hydroxy acid products with complete stereochemical transfer. The silylene transfer methodology was utilized in an attempt to synthesize the natural product (+)-latifoline, previously reported by Wood in 2001. Unfortunately, exocyclic stereocenters in the Ireland–Claisen rearrangement reduced the diastereoselectivity of the transformation, rendering it completely unselective. An additional target, ferupennin F, was selected that avoided complications involved with the prior application. During the investigation, several γ-lactones were synthesized diastereoselectively. Efforts towards the total synthesis of ferupennin F are ongoing.

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