Silica-Catalysed and Highly Stereoselective Convergent and Nonconvergent Rearrangements of Menthone Enol Acetate Epoxides: Easy Access to the Four α-Hydroxymenthone Stereoisomers
to the biocatalytic access of structurally useful α-hydroxy ketones, we made the unexpected observation that epoxy enolacetates derived from (+)- and (–)-menthone stereoselectivelyrearranged on exposure to silica through a diastereoselective process, providing easyaccess to the complete set of α-hydroxymenthonestereoisomers. The absolute configurations of the fourstereoisomers were unambiguously