Diastereoselective Protocols for the Synthesis of 2,3-<i>trans</i>- and 2,3-<i>cis</i>-6-Methoxy-morpholine-2-carboxylic Acid Derivatives
作者:Michele Penso、Francesca Foschi、Sara Pellegrino、Andrea Testa、Maria Luisa Gelmi
DOI:10.1021/jo300221y
日期:2012.4.6
were realized in few steps, through the condensation between 5,6-diethoxy-5,6-dimethyl-1,4-dioxan-2-one and an appropriate imine, which is the key reaction to control the C2–C3 relative stereochemistry, followed by a methanolysis/ring-closure tandem reaction sequence. In particular, 2,3-trans-morpholines derive from the R*,S*-product of the acid condensation of N-functionalized alkylimines with the
通过5之间的缩合,只需几个步骤即可实现两种高选择性合成2,3-反式和2,3-顺式-6-甲氧基-3-取代的吗啉-2-羧酸酯的非对映选择性和直接方法。6-二乙氧基-5,6-二甲基-1,4-二恶烷-2-酮和适当的亚胺,是控制C2-C3相对立体化学的关键反应,其后是甲醇裂解/闭环串联反应序列。特别地,2,3-反式吗啉衍生自N-官能化的亚烷基亚胺与上述内酯的甲硅烷基乙烯酮缩醛的酸缩合的R *,S *产物,而2,3-顺式吗啉衍生自N-官能化的亚烷基甲硅烷基乙缩醛的酸缩合产物。R *,R * -N-甲苯磺胺与内酯的基本缩合产物。