2,5-Disubstituted pyrrolidines: synthesis by enamine reduction and subsequent regioselective and diastereoselective alkylations
作者:Syed Raziullah Hussaini、Mark G. Moloney
DOI:10.1039/b604183c
日期:——
diastereoselective synthesis of 2,5-disubstitutedpyrrolidines by reduction of enamines derived from pyroglutamic acid is reported; the nature of nitrogen protection was found to be critical for the stereochemical control of the reaction outcome. Regioselective manipulation of the C-2 and C-5 substituents is possible, providing access to differently substituted pyrrolidines for a limited number of cases
Synthesis of specifically stable-isotope-labeled l-proline via L-glutamic acid
作者:J. J. Cappon、G. A. M. van der Walle、P. J. E. Verdegem、J. Raap、J. Lugtenburg
DOI:10.1002/recl.19921111204
日期:——
steps. In earlier work we described the preparation of L-glutamicacid isotopically labeled at any position or combination of positions starting from simple highly enriched synthons. The synthetic scheme in this publication makes L-proline, 13C- or 15N-labeled at any position or combination of positions, easily available. The labeled L-prolines are characterized by 1H-, 13C- and 15N-NMR and mass spectrometry
(3,4- 13 C 2)-L-脯氨酸和(15N)-L-脯氨酸是通过单一方案由相应标记的L-谷氨酸制备的,产率高,克级。合成途径基于L-谷氨酸与L-5-氧代脯氨酸的闭环和5-酰胺官能团的选择性还原,而不会干扰2-羧酸酯官能团和不对称中心。通过首先将酰胺转化为相应的硫代酰胺,然后结合保护和脱保护步骤,使用氢化三丁基锡将硫代酰胺还原为胺,从而实现选择性还原。在较早的工作中,我们描述了从简单的高度富集的合成子开始,在任何位置或位置组合处同位素标记的L-谷氨酸的制备方法。该出版物中的合成方案使L-脯氨酸13容易在任何位置或位置组合上使用C或15 N标签标记。标记的L-脯氨酸的特征在于1 H-,13 C-和15 N-NMR和质谱。
Chirospecific syntheses of (+)- and (-)-anatoxin a
作者:John S. Petersen、Gregor Fels、Henry Rapoport
DOI:10.1021/ja00328a040
日期:1984.8
Andersen, Torben P.; Rasmussen, Preben B.; Thomsen, Ib, Liebigs Annalen der Chemie, 1986, # 2, p. 269 - 279
作者:Andersen, Torben P.、Rasmussen, Preben B.、Thomsen, Ib、Lawesson, Sven-Olov、Joergensen, Palle、Lindhardt, Peter
DOI:——
日期:——
FANG, FRANCIS G.;PRATO, MAURIZIO;KIM, GUNCHEOL;DANISHEFSKY, SAMUEL J., TETRAHEDRON LETT., 30,(1989) N8, C. 3625-3628
作者:FANG, FRANCIS G.、PRATO, MAURIZIO、KIM, GUNCHEOL、DANISHEFSKY, SAMUEL J.