A novel enantiopure tricyclic beta-lactam via stereoselective intramolecular nitrilimine cycloaddition

作者：Del Buttero Paola^*; Molteni Giorgio; Pilati Tullio

来源：Tetrahedron: Asymmetry , 2010, 21(21-22): 2607-2611.

DOI：10.1016/j.tetasy.2010.10.018

Starting from the Staudinger [2+2] cycloaddition between the 1-azadiene 1 and acetoxyacetylketene generated in situ from acetoxyacetyl chloride we developed a seven-step synthesis of the novel azeto[3' 4' 2 3]pyrano[4 5-c]pyrazole skeleton 9 in both racemic and enantiopure forms Silver carbonate treatment of the functionalised hydrazonoyl chloride 7 promoted in situ generation of the corresponding nitrilimine 8 which underwent a clean stereoselective cycloaddition to the target tricyclic beta-lactam 9 The key step of the synthetic pathway leading

• 出版日期2010-11-25