End-group differentiating ozonolysis of norbornene systems to access to highly substituted cyclopentane rings

Abstract

The end-group-differentiating ozonolysis concept is discussed, with an emphasis on norbornene systems. Different remote functional groups in endo positions in norbornene derivatives are able to direct the primary ozonide fragmentation. By analysis of the factors affecting the regioselectivity, a rule to predict the direction of the primary ozonide rupture is formulated. These reactions give access to highly substituted cyclopentane rings and provide opportunities for their subsequent regioselective manipulation.