1 H Nmr structural analysis of azabicyclospirohydantoins

Based on the data from 1 H nmr spectra, the structure and spatial configuration of the ahove mentioned hydantoins are established. In the 3‐alkyl‐3‐azabicyelo[3.3.f ]nonane‐9‐spiro‐5′‐hydantoins analyzed, we confirm the chair‐chair configuration and the presence of only one stereoisomer at the spiro carbon atom (with the C 4 ′=() group axial with regard to the piperidine ring). In the 3,7‐dialkyl‐3,7‐diazabieyclo[3.3.1 ]nonane‐9‐spiro‐5′‐hydantoins analyzed, we also confirm the chair‐chair configuration and we calculate the percentage of the two stereoisomers when they exist.