Efficient Diastereoselective Synthesis of (2R,3R,4R)-2-Amino-3-hydroxy-4,5-dimethylhexanoic Acid, the Lactone Linkage Unit of Homophymine A

For the total synthesis of novel cyclodepsipeptide homophymine A, (2R,3R,4R)-2-amino-3-hydroxy-4,5-dimethylhexanoic acid was successfully synthesized by Evans' asymmetric alkylation and the anti-selective asymmetric hydrogenation of a chiral alpha-amino-beta-keto ester as the key steps.