The ''abbreviated'' model of NAD, denin-9-yl)-2-hydroxypropyl]-3-carba
moylpyridinium chloride (VIIIa), and its 2,6-diaminopurine (VIIIb), 3-
deazaadenine (VIIIc), guanine (VIIId) and cytosine (VIIIe) analogues w
ere prepared by the Zincke reaction. The (R)-isomer of the adenine mod
el VIIIa (compound IX) was prepared for chiroptical studies. As shown
by NMR, UV and CD spectra, neither in dimethyl sulfoxide nor in water
any intramolecular pi-pi interactions exist between the heteroaromatic
systems.