Formation, reactions, and NMR spectra of 1,20-cycloatidanes

Imines derived from the alkaloid atisine gave N-acetyl 1,20-cycloatidane derivatives when heated with acetic anhydride. Vigorous alkaline hydrolysis cleaved the cyclopropane ring, regenerating the parent imine. The 1 H and 13 C NMR spectra of several 1,20-cyclo derivatives have been assigned and compared to those of the parent imines 2 . All of the N-acetyl compounds showed doubling of the majority of the NMR resonances, due to amide rotamers. The effects of the cyclopropane ring current are noted.