Model studies of pyrrolizidine synthesis

Model studies of rearrangements of N-chloro amines leading to pyrrolizidine and indolizidine ring systems were investigated. Upon treatment with silver cation, an N-chloro amine forms a nitremium ion, which can rearrange to another amine. The rearrangement of N-chloronortropane to pyrrolizidine and N-chloronorgranatanane to a substituted indolizidine is described. An attempt to make a substituted cyclobutanone, an intermediate in another possible route to pyrrolizidine, is also described.

The ¹³C nmr chemical shifts of a number of N-substituted nortropanes and norgranatananes are reported.