Solution conformations of muscarine and some analogue.

Proton magnetic spectra have been recorded for muscarine and two biologically active cyclopentane analogues. In order to observe homonuclear intramolecular nuclear Overhauser effects, the -N+(CH3)3 signal was irradiated and increases in integrated intensities for other key signals in the molecule were observed. The results indicate that the quaternary side chain in these compounds is in an extended conformation in aqueous solution.