Stereoselective Synthesis of (2S, 4R)??4??Hydroxypipecolic Acid

EG Occhiato, D Scarpi, A Guarna

Index: Occhiato, Ernesto G.; Scarpi, Dina; Guarna, Antonio European Journal of Organic Chemistry, 2008 , # 3 p. 524 - 531

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Citation Number: 14

Abstract

Abstract A new synthetic route to enantiopure (2S, 4R)-4-hydroxypipecolic acid from commercial ethyl (3S)-4-chloro-3-hydroxybutanoate is reported. The synthesis is based on the Pd-catalyzed methoxycarbonylation of a 4-alkoxy-substituted δ-valerolactam-derived vinyl triflate followed by the stereocontrolled hydrogenation of the enamine double bond. The final product was obtained after exhaustive hydrolysis in 20% yield over 10 steps.(© ...