Kauffman, Goss S. Watson, Paul S. Nugent, William A. Strategy for the Enantioselective Synthesis of <i>trans</i>-2,4-Disubstituted Piperidines:  Application to the CCR3 Antagonist IS811 A strategy for the enantioselective synthesis of <i>trans</i>-2,4-disubstituted piperidines is proposed and applied to the preparation of IS811, a potent CCR3 antagonist. The C2 stereocenter is derived from commercial (<i>R</i>)-epichlorohydrin, while the C4 stereocenter is installed via diastereoselective hydrogenation of an α,β-unsaturated lactone intermediate. Inversion of the original stereocenter via an efficient intramolecular S<sub>N</sub>2 amination affords the piperidine core of IS811. An improved protocol for the lithiation of ethyl propiolate is reported. CCR 3 antagonist;diastereoselective hydrogenation;piperidine core;ethyl propiolate;enantioselective synthesis;811A strategy;C 2 stereocenter;intramolecular SN 2 amination;CCR 3 Antagonist;tran;C 4 stereocenter;Enantioselective Synthesis 2006-11-10
    https://acs.figshare.com/articles/journal_contribution/Strategy_for_the_Enantioselective_Synthesis_of_i_trans_i_2_4_Disubstituted_Piperidines_Application_to_the_CCR3_Antagonist_IS811/3048799
10.1021/jo0616963.s001