作者:Adrien Soret、Christine Müller、Régis Guillot、Luis Blanco、Sandrine Deloisy
DOI:10.1016/j.tet.2010.11.080
日期:2011.1
A microwave-assisted tandem [3+2] cycloaddition/retro-Diels–Alder reaction of azomethine ylides derived from imines of α-amino esters to dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate derivatives is described. The procedure delivers, in a short reaction time, pyrrolines in high yields. In a such sequence, the oxanorbornadiene derivatives behave as masked forms of dimethyl acetylenedicarboxylate
微波辅助串联[3 + 2]环加成反应/复古Diels-Alder反应,由α-氨基酯的亚胺衍生而来的甲亚胺基化物与二甲基7-氧杂双环[2.2.1] hepta-2,5-diene-2,3描述了-二羧酸酯衍生物。该方法在短的反应时间内以高产率提供吡咯啉。按照这样的顺序,氧杂降冰片二烯衍生物表现为乙炔二羧酸二甲酯的掩蔽形式。随后用DDQ氧化合成的3-吡咯啉可得到2 H-吡咯,产率在76-88%的范围内。如果此三步序列在未取代的7-氧杂双环庚二烯基羧酸盐上进行,则避免纯化中间体3-吡咯啉,在不到2小时的时间内提供2 H-吡咯。