A Fries-Type Rearrangement Strategy for the Construction of Stereodefined Quaternary Pseudoanomeric Centers: An Entry into C -Naphthyl Ketosides.

The stereodefined construction of quaternary pseudoanomeric centers by way of a BF 3 ·Et 2 O-catalyzed, Fries-type rearrangement of O -ketosides is described. This method provides new access to C -naphthyl ketosides related to biologically relevant products with good to complete stereocontrol in favor of the β product.