Regio‐, Diastereo‐, and Enantioselective Synthesis of vic‐Diols via α‐Silyl Ketones According to the SAMP/RAMP Hydrazone Method

Abstract α‐Silylated ketones 5 or 10 of high enantiomeric purity (ee ≥ 90%) are easily available by silylation or silylation/alkylation of ketones 1 or 6 , resp., according to the SAMP/RAMP hydrazone method. Reduction of 5 or 10 with L‐selectride™, followed by oxidative cleavage of the C–Si bond, leads to vic ‐diols 11 – 13 with high diastereoselectivity (de ≥ 90%) and without racemization. The stereoselectivity of the reduction depends on the structure of the α‐silyl ketones 5 or 10 , the reducing reagents, and the solvents used.