title: Remote functionalization of C60 with enantiomerically pure cyclo-[2]-malonate tethers bearing C12 and C14 spacers: synthetic access to bisadducts of C60 with the inherently chiral trans-3 addition pattern.
abstract: In this Article, we describe the synthesis of two optically pure diols bearing a 1,2-diol moiety masked as an isopropylidene acetal group and long alkyl chains comprised of 12 and 14 carbon atoms, respectively. The synthetic methodology that was developed offers a general way for the synthesis of optically pure diols with long alkyl chains. Diols (-)-4 and (-)-9 were subjected to a condensation reaction with malonyl dichloride to afford two cyclo-[2]-malonate tethers that were separated by column chromatography in optically pure form. The bismalonates (-)-4b and (-)-9b proved to be excellent tethers for the regioselective Bingel functionalization of C60, furnishing in a regioselective manner the corresponding (f,s)C and (f,s)A trans-3 bisadducts with low diastereoselectivity but in very good to excellent total yields. In both cases, the formed trans-3 bisadducts were isolated in pure form by simple column chromatography and were fully characterized. The successful acetal deprotection of the synthesized trans-3 bisadducts afforded quantitatively the corresponding polyalcohols, which represent novel chiral fullerene compounds equipped with glycol moieties.
authors.affiliation: Department of Chemistry, University of Cyprus, University Str 1, Building no. 13, Aglantzia, 2109 Nicosia, Cyprus.
authors.forename: Maria
authors.initials: M
authors.lastname: Riala
authors.forename: Nikos
authors.initials: N
authors.lastname: Chronakis
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry*; D008314:Malonates / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000438:Alcohols; D037741:Fullerenes; D008314:Malonates; C069837:fullerene C60