Silicon‐Directed Regio‐ and Enantioselective Synthesis of α‐Hydroxy‐ketones Preliminary Communication

Abstract α‐Silylated ketones ( S )− 2 (ee ≥ 98%), easily available through silylation or silylation/alkylation from ketones 1 using the (−)‐( S )‐1‐amino‐2‐(methoxymethyl)pyrrolidine (SAMP)−/(+)‐( R )‐1‐amino‐2‐(methoxymethyl)pyrrolidine (RAMP)‐hydrazone method, are oxidized to give α‐hydroxy‐ketones ( R )− 5 of high enantiomeric purity (ee ≥ 98%) and in good overall yields (51‐70%). The key step of the procedure is the silicon‐directed diastereoselective oxidation of the corresponding silyl enol ethers of ( S )− 2 , with m ‐chloroperbenzoic acid or 3‐phenyl‐2‐(phenylsulfonyl)oxaziridine, followed by flash chromatography and desilylation.