作者:Achille Barco、Nikla Baricordi、Simonetta Benetti、Carmela De Risi、Gian P. Pollini、Vinicio Zanirato
DOI:10.1016/j.tet.2007.03.056
日期:2007.5
Intramolecular Michael reaction of methyl (R)-6-(tert-butoxycarbonylamino)oxy-4-hydroxy-2-hexenoate, in turn obtained from tert-butyl (R)-3-hydroxy-4-pentenoate, paved the way to the synthesis of both enantiomers of 2-oxa-6-azabicyclo[3.3.0]octan-3-one (the Geissman–Waiss lactone), a precursor for necine bases. Key intermediates in this approach were represented by enantiomeric bicyclic lactones incorporating
(R)-6-(叔-丁氧基羰基氨基)氧基-4-羟基-2-己烯酸甲酯的分子内迈克尔反应,又是从(R)-3-羟基-4-戊烯酸叔丁酯获得的,合成2-oxa-6-氮杂双环[3.3.0] octan-3-one(Geissman-Waiss内酯)的两种对映体(烟碱的前体)。该方法中的关键中间体以并入[1,2]-恶嗪烷核的对映体双环内酯为代表,该化合物已方便地用于通过合成方案来安装目标化合物的吡咯烷骨架,其特征在于还原了氮-氧键和分子内小号ñ 2反应。