6-tetrahydropyridine intermediates took place smoothly in the presence of a Pd/C catalyst to give trans-2,3-disubstituted piperidines in good yields and in a highly stereoselective manner. The total synthesis of optically active (2S,3R)-(−)-epi-CP-99,994 was achieved in six-steps from an unsaturated piperidine.
                                    由β-
氨基-α-亚甲基酯容易地以三步制备手性2,3-反式取代的
哌啶,所述β-
氨基-α-亚甲基酯是通过手性亚
磺胺的Michael / Mannich多米诺反应制备的。所述的加氢Ñ
甲苯磺酰基-2-芳基-1,2,5,6-四氢
吡啶中间体发生顺利在Pd / C催化剂的存在下,得到反式以良好产率和在一个高度-2,3-二取代
哌啶类立体选择性的方式。从不饱和
哌啶中分六步完成了旋光(2S,3R)-(-)- Epi- CP-99,994的总合成。