Synthesis and study of novel fulleropyrrolidines bearing biologically active 1,4-dihydropyridines

New fulleropyrrolidines endowed with chlorine-containing biological active 1,4-dihydropyridines (1,4-DHPs) have been synthesised from the respective formyl substituted 1,4-DHPs by following Pratoʹs procedure. The presence of the chlorine atom on C2 of the 1,4-DHP ring brings about important spectroscopical and structural differences in compounds related to the parent hydrogen-containing . The mass spectroscopy study reveals different fragmentation patterns for fulleropyrrolidines and their precursors 1,4-DHPs, as well as with . Semiempirical calculations (AM1 and PM3) predict a most stable stereoisomer in all cases (RS for ) and the same RR for . The presence of chlorine atom in is responsible for the higher calculated conformational energy barriers in comparison with . The geometry of the 1,4-DHP shows that the presence of fullerene unit does not significantly alter the required conformation for biological activity.