3,7-Dioxa-1-azabicyclo[3.3.0]octanes Substituted at the C-5 Position− From Local to Global Stereochemistry
Abstract
Multiple approaches are described for the elucidation of the stereochemistry in solution (high‐resolution NMR spectroscopy) and in the solid state (X‐ray diffractometry) that are based on ab initio calculations (level RHF/6‐31G*) of some representative 3,7‐dioxa‐1‐azabicyclo[3.3.0]octanes. The results are presented in terms of conformational analysis, anomeric effects, chelating properties and aggregation phenomena. The significance of these findings with respect to diastereoselective synthesis is discussed.