Stereodivergent Resolution of Oxabicyclic Ketones: Preparation of Key Intermediates for Platensimycin and Other Natural Products

An improved methodology for the preparation of enantiopure oxabicyclo[3.2.1]­octadienes via a stereodivergent resolution is reported. High catalyst control proximal to the oxabridged stereocenter produces readily separable diastereomers in high yield (>92%) and with excellent optical purity (>95% ee). This resolution strategy is amenable to large-scale preparations, and the utility of the resolution was further demonstrated in the asymmetric preparation of a key intermediate used in the synthesis of the antibiotic (−)-platensimycin.