Stereoselective Synthesis of the Western Fragment of Vancoresmycin

The synthesis of the western fragment of vancoresmycin was accomplished in a highly modular and stereoselective manner. Central to this strategy was a modified Cu-catalyzed β-boration protocol for α,β-unsaturated enones, which enabled convergent construction of complex, densely functionalized polyketide architectures with high stereocontrol. Application to a structurally demanding fragment highlighted its potential as a general tool for 1,3-diol construction. In addition, NMR comparison confirmed the stereochemical assignment of the western part of vancoresmycin.