A practical synthesis of (R)-homopipecolinic acid methyl ester and (R)-homoproline methyl ester was performed utilizing (i) a direct intramolecular cyclization of ω-chloro-β-enamino esters and, which were prepared from available (S)-1-phenylethylamine or (S)-1-(1- naphthyl) ethylamine and ω-chloro-β-keto esters and, respectively and (ii) a highly diastereoselective NaBH4 reduction followed by hydrogenolysis. The present method is a ...
