Stereoselective synthesis of cis-2,6-disubstituted piperidines from 1,2-cyclic sulfamidates
作者:Mustafa Eskici、Abdullah Karanfil
DOI:10.1016/j.tet.2019.01.030
日期:2019.3
Diastereoselective synthesis of cis-2,6-disubstituted piperidines from 1,2-cyclic sulfamidates is described. Regioselective ring-opening reactions of 1,2-cyclic sulfamidates derived from L-phenylalanine, alanine, valine, norvaline with the ketal protected acetylide with a phenyl substituent proceed smoothly to form the N-sulfamate intermediates which on acidic hydrolysis give alkynylated amines with
描述了由1,2-环氨基磺酸盐的非对映选择性合成顺式-2,6-二取代的哌啶。衍生自L-苯丙氨酸,丙氨酸,缬氨酸,正缬氨酸的1,2-环氨基磺酸盐与带有苯基取代基的缩酮保护的乙炔的区域选择性开环反应可顺利进行,以形成N-氨基磺酸酯中间体,该中间体在酸性水解下可生成炔基化胺。缩酮组完好无损。烷基化胺的氢化,脱苄基化,缩酮去保护,随后的环化(氨基酮)的环化和环状亚胺离子中间体的立体选择性加氢得到相应的顺式-2,6-二取代哌啶具有高非对映选择性(98%≥de)和良好的化学收率(68–86%)。本方法提供了立体选择合成顺式-2,6-二取代哌啶的新途径。