Synthesis of All the Diastereomers of 2‐Amino‐3‐hydroxy‐4,5‐dimethylhexanoic Acid

Abstract

AbstractHerein, we describe an efficient stereoselective synthesis of all the diastereomers of 2‐amino‐3‐hydroxy‐4,5‐dimethylhexanoic acid. The γ‐branched carbon skeleton was set up by reaction of Garner's aldehyde with 2‐lithio‐3‐methyl‐2‐butene. Hydrogenation (Pd/C catalyst) of the tetrasubstituted olefin proceeded smoothly with acceptable stereoselectivity, depending on the diastereomer hydrogenated. The final compounds were then obtained in 12–18 % overall yield through intramolecular cyclization, Jones oxidation, and hydrolysis in 5–7 steps from Garner's aldehyde.