Two-Directional Desymmetrization by Double 1,4-Addition of Silicon and Boron Nucleophiles

Abstract

The two-directional desymmetrization of prochiral precursors with α,β-unsaturated branches by catalyst-controlled 1,4-addition of silicon and likewise boron nucleophiles allows for a general enantioselective access to <i>syn</i>,<i>anti</i>-triols with 1,<i>n</i> + 1,2<i>n</i> + 1 (<i>n</i> = 2 and 3) substitution patterns. The utility is demonstrated in the synthesis of the C17–C25 fragment of dermostatin A