Practical method for the synthesis of (R)-homopipecolinic acid and (R)-homoproline esters from ω-chloroalkanoic acids and available chiral amines

N Hashimoto, T Funatomi, T Misaki, Y Tanabe

Index: Hashimoto, Norio; Funatomi, Takashi; Misaki, Tomonori; Tanabe, Yoo Tetrahedron, 2006 , vol. 62, # 10 p. 2214 - 2223

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Citation Number: 6

Abstract

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 ...