(3S)?-3-[[(1,1-Dimethylethoxy)?carbonyl]?amino]?-4-hydroxy-butanoic Acid Methyl Ester is used to prepare CCR3 antagonists with picomolar inhibition potency against eosinophil chemotaxis. It is also used to synthesize aryl substituted, β- and γ-amino acids in DMF using functionalized zinc reagents.