bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Clefts Derived from 9,9′‐spirobi[9H‐fluorene] for enantioselective complexation of pyranosides and dicarboxylic acids
Authors: Cuntze Jens , Owens Linda , Alcázar Victoria , Seiler Paul , Diederich François 
Published: December 2004

AbstractThe molecular clefts (R)‐ and (S)‐3, incorporating 9,9′‐spirobi[9H‐fluorene] as a spacer and two N‐(5,7‐dimethyl‐1,8‐naphthyridin‐2‐yl)carboxamide (CONH(naphthy)) units as H‐bonding sites were prepared via the bis(succinimid‐N‐yl esters) of (R)‐and (S)‐9,9′‐spirobi[9H‐fluorene]‐2,2′‐dicarboxylic acid (5). Derivative 6, with one CONH(naphthy) unit and one succinimid‐N‐yl ester residue allowed easy access to spirobifluorene clefts with two different H‐bonding sites, as exemplified by the synthesis of 4. Binding studies with (R)‐ and (S)‐3 and optically active dicarboxylic acids in CDCl3 exhibited differences in free energy of the formed diastereoisomeric complexes (Δ(ΔGº)) between 0.5 and 1.6 kcal mol−1 (T 300 K). Similar enantioselectivities were observed with the spirobifluorene clefts (R)‐ and (S)‐1, bearing two N‐(6‐methylpyridin‐2‐yl)carboxamide (CONH(py)) H‐bonding sites. The thermodynamic quantities ΔHº and ΔSº for the recognition processes with (R)‐ and (S)‐1 were determined by variable‐temperature 1H‐NMR titrations and compared to those with (R)‐ and (S)‐2, which have two CONH(py) moieties attached to the 6,6′‐positions of a conformationally more flexible 1,1′‐binaphthyl cleft. All association processes showed high enthalpic driving forces which are partially compensated by unfavorable changes in entropy. Pyranosides bind to the optically active clefts 1 and 3 in CDCl3 with −ΔGº = 3.0–4.3 kcal mol−1. Diastereoisomeric selectivities up to 1.2 kcal mol−1 and enantioselectivities up to 0.4 kcal mol−1 were observed. Cleft 4 and N‐(5,7‐dimethyl‐1,8‐naphthyridin‐2‐yl)acetamide (25) complexed pyranosides 22–24 as effectively as 3 indicating that only one CONH(naphthy) site in 3 associates strongly with the sugar derivatives. Based on the X‐ray crystal structure of 3, a computer model for the complex between (S)‐3 and pyranoside 22 was constructed. Molecular‐dynamics (MD) simulations showed that differential geometrical constraints are at the origin of the high enantioselectivity in the complexation of dicarboxylic acid (S)‐7 by (R)‐ and (S)‐1 and (R)‐ and (S)‐3.
Total Synthesis of Crenulatan Diterpenes: Strategy and stereocontrolled construction of a bicyclic keto‐lactone building block
Authors: He Wei , Pinard Emmanuel , Paquette Leo A. 
Published: December 2004

AbstractThe bicyclic keto lactone 26 was synthesized for the purpose of developing a viable route to marine diterpenes of the crenulatan type. Following the efficient conversion of (S)‐citronellol (5) to the allylated alcohol 9a (Scheme 2), the αβ‐unsaturated lactone 12 was efficiently accessed in preparation for stereocontrolled conjugate addition. The hydroxymethyl equivalent most suited to this task was (i‐PrO)Me2SiCH2MgCl, which gave 13 predominantly in the presence of CuI and Me3SiCl. Once the OH group was deprotected (→ 14), it proved an easy matter to implement acid‐catalyzed isomerization to lactone 15, oxidation of which gave the pivotal aldehyde 16. Condensation of 16 with PhSeCH2Li led via 21 to 22 (Scheme 3). Once the OH group was protected (→ 22b), it proved possible to effect aldolization with crotonaldehyde (→ 23). Exposure of 23 to acid gave the sub‐target compound 25. Its subsequent oxidation and thermal activation resulted in sequential selenoxide elimination with Claisen rearrangement (→ 26). The structural features of 26 require that a chair‐like transition state be adopted during the [3.3]sigmatropic event. With the clarification of these issues, a highly serviceable and more advanced assault on the crenulatans should prove capable of being mounted.
Synthesis of Potential Inhibitors of Ethylene Biosynthesis: The diastereoisomers of 1‐amino‐2‐bromocyclopropanecarboxylic acid
Authors: Wick Lukas , Tamm Christoph , Boller Thomas 
Published: December 2004

AbstractThe preparation of the diastereoisomers of 1‐amino‐2‐bromocyclopropanecarboxylic acid is described using the methyl (1RS, 5SR)‐2‐oxo‐3‐oxabicyclo[3.1.0]hexane‐1‐carboxylate 5 as starting material. The key step is the oxidation of 9 with subsequent radical introduction of bromine according to the Barton procedure. The 2‐bromo‐cyclopropanecarboxylates cis‐11 and trans‐11 were obtained as diastereoisomer mixture in a ratio of 3:1. They were converted into cis‐ and trans‐esters 12 and the acids 13.
Synthesis of Galactose‐ and N‐Acetylglucosamine‐Derived Tetrazoles and their evaluation as β‐glycosidase inhibitors
Authors: Heightman Thomas D. , Ermert Philipp , Klein Daniela , Vasella Andrea 
Published: December 2004

AbstractThe title compounds 6 and 7 have been prepared from the known 2,3‐di‐O‐benzyl‐4,6‐O‐benzylidene‐D‐galactose (18) and N2‐acetyl‐tri‐O‐benzyl‐D‐glucosamine oxime (29) in eight and six steps, respectively. The azidonitrile leading to the benzylated galacto‐tetrazole 16 was prepared from 14 and cyclized under the conditions of its formation (Scheme 1). The alcohol 13 was obtained by oxidation of 10 followed by reduction. Better yields and diastereoselectivities were realized, when the benzylidene‐protected D‐galacto‐alcohol 20 was subjected to oxido‐reduction, yielding the L‐altro‐alcohol 22 via the ketone 21 (Scheme 2). Treatment of the corresponding tosylate 24 with NaN3 yielded the tetrazole 25, which was deprotected to 6. The tetrabenzyl ether 16 (from 14, or from 25 via 27) was reduced to 28 and deprotected to give the known deoxygalactostain 8 (Scheme 2). Oxidation of the hydroxynitrile 30, derived from 29, followed by reduction of 32 yielded mostly the L‐ido‐hydroxynitrile (Scheme 3), which was tosylated and treated with NaN3 to give the tetrazole 35a and its manno‐isomer 36a, while Al(N3)3 yielded (E)‐ and (Z)‐38 (Scheme 4). The intermediate azide 39 was isolated besides 40 when NH4N3/DMF was used; thermolysis of 39 gave mostly 35a, which was deprotected to 7, besides some elimination product 41. Both 6 and 7 are stable in the pH range 1–10; at pH 12, 6 is unaffected but, 7 shows some epimerization to the manno‐configurated isomer 43. The tetrazole 6 is a competitive inhibitor of the β‐galactosidases from E. coli (K1 = 1 μM, pH 6.8) and bovine liver (K1 = 0.8 μM, pH 7.0); the N‐acetyl‐β‐D‐glucosaminidase from bovine kidney is competitively inhibited by 7 (K1 ≊ 0.2 μM, pH 4.1).
Pteridines. Part CVI. Isolation and characterization of limipterin (1‐O‐(L‐erythro‐biopterin‐2′‐yl)‐β‐N‐acetylglucosamine) and its 5,6,7,8‐tetrahydro derivative from green sulfur bacterium Chlorobium limicola f. thiosulfatophilum NCIB 8327
Authors: Cha Ki W. , Pfleiderer Wolfgang , Yim Jeongbin J. 
Published: December 2004

AbstractA new pteridine compound was isolated from green sulfur photosynthetic bacteria, Chlorobium limicola f. thiosulfatophilum NCIB 8327. The structure of this pterin derivative was established to be 1‐O‐(L‐erythro‐5,6,7,8‐ tetrahydropterin‐2′‐yl)‐β‐N‐acetylglucosamine (1) from 1H‐NMR and CD spectra as well as from various mass spectrometric techniques and chemical‐cleavage techniques. Upon acid hydrolysis of 1, equimolar amounts of biopterin (2) and N‐acetylglucosamine were produced. The structure of the hydrolysis product 2 was confirmed by comparing its NMR, UV, CD, and MS and its chromatographical behavior with those of an authentic specimen. N‐Acetylglucosamine was identified by an enzymatic hydrolysis experiment as well as by NMR and thin layer chromatography. Electrospray (ES), fast‐atom‐bombardment (FAB), and thermospray (TS) mass spectrometry of 1 yielded an MH+ at m/z 441. Periodate‐oxidation experiments of the intact molecule 1 and of its hydrolysis product 2 are consistent with the proposed structure. Differential I2 oxidation experiments with the native compound showed that the in vivo oxidation state of this pterin is its tetrahydro form. We propose the trivial name ‘limipterin’ for this new compound.
1‐Lithio‐2,2‐diphenyl‐1‐(phenylsulfonyl)ethen: Synthese und Kristallstruktur
Authors: Müller Jürgen , Neuburger Markus , Zehnder Margareta 
Published: December 2004

Syntheses and Crystal Structure of 1‐Lithio‐2,2‐diphenyl‐1‐(phenylsulfonyl)etheneCrystals of [1‐lithio‐2,2‐diphenyl‐1‐(phenylsulfonyl)ethene]– N,N,N′,N′ ‐tetramethylethylenediamine (2/2) (2) were prepared by addition of BuLi to 1,1‐diphenyl‐2‐(phenylsulfonyl)ethene (1) in the presence of N,N,N′,N′ ‐tetramethylethylenediamine (TMEDA) at low temperature. The X‐ray structure analysis shows a centrosymmetric dimer bridged over an eight‐membered (LiOSO)2 ring. There are no Li–C contacts to the C(α) atoms. Both Li cations are tetracoordinated via the sulfonyl O‐atoms and the N‐atoms of the TMEDA ligand. The X‐ray structure analysis of 1,1‐diphenyl‐2‐(phenylsulfonyl)ethene (1) also was determined to compare interatomic distances and angles.
The Low‐Temperature UV/VIS Absorption Spectrum of [14]Annulene
Authors: Baumann Harold , Oth Jean F. M. 
Published: December 2004

AbstractThe UV/VIS absorption spectrum of [14]annulene was measured in 3‐methylpentane at room and liquid‐N2 temperatures and interpreted by the CNDO/S‐CI method. This comparison between experiment and theory supports a structure with π‐bond delocalization for this molecule.
Acyclic Tetraethynylethene Molecular Scaffolding: Multinanometer‐sized linearly conjugated rods with the poly(triacetylene) backbone and cross‐conjugated expanded dendralenes
Authors: Boldi Armen M. , Anthony John , Gramlich Volker , Knobler Carolyn B. , Boudon Corinne , Gisselbrecht Jean‐Paul , Gross Maurice , Diederich François 
Published: December 2004

AbstractDerivatives of fully cross‐conjugated tetraethynylethene (3,4‐diethynylhex‐3‐ene‐1,5‐diyne) 1 are versatile precursors to multinanometer‐sized molecular rods with all‐C‐backbones. Oxidative polymerization (CuCl, N,N,N′,N′‐tetramethylethylenthylenediamine (TMEDA), O2) of the trans‐bis‐deprotected trans‐bis(triisopropylsilyl)‐protected tetraethynylethene 2 yielded, after end‐capping with phenylacetylene, the remarkably stable, soluble oligomers 3–7 with a persilylethynylated poly(triacetylene) (PTA) backbone [(CCCRCRCC)n] and a length of 19.4 (3), 26.8 (4), 34.3 (5), 41.8 (6), and 49.2 (7) Å (Scheme 1). These compounds underwent facile one‐electron reductions with the number of reversible reduction steps being equal to the number of tetraethynylethene moieties in each molecular rod. Oxidative Eglinton‐Glaser homo‐coupling of tetraethynylethenes 8–10 with a single free ethynyl group provided the fully silyl‐protected 3,4,9,10‐tetraethynyl‐substituted dodeca‐3,9‐diene‐1,5,7,11‐tetraynes 11–13 (Scheme 2) and, after alkyne deprotection, the novel hydrocarbon 14, a C20H6 isomer, and its partially silyl‐protected derivative 15. Oxidative hetero‐coupling between two different tetraethynylethene derivatives, one with a single and the other with two free terminal ethynyl groups, yielded the extended chromophores 16–21 composed of 3 or 4 tetraethynylethene moieties (Scheme 3). The linearly conjugated oligomers 16 and 17 with the PTA backbone are isomeric to 19 and 20, respectively, which are members of the cross‐conjugated expanded dendralenes, i.e., dendralenes with butadiynediyl fragments inserted between each pair of double bonds [(CCC(CR2)CC)n]. The electronic absorption spectra of these compounds were compared and analyzed in terms of the competition between linear and cross‐conjugation in determining the extent of π‐electron delocalization. Although steric factors on π‐electron conjugation remain to be clarified, this analysis strongly suggests that cross‐conjugation is not an efficient mechanism for π‐electron delocalization. All extended acetylenic‐olefinic chromophores considered in this study exhibited remarkably high stability and did not decompose when exposed to laboratory air and light for months. In agreement with this observation, electrochemical studies demonstrated that the compounds are difficult to oxidize with the oxidation potentials in THF (0.1M(Bu4N)PF6) being higher than 1.0 V (vs. the ferrocene/ferrocenium couple).
Stereoselective Partial Synthesis of (+)‐Pisiferic Acid
Authors: Geiwiz Jürgen , Haslinger Ernst 
Published: December 2004

Abstract(+)‐Pisiferic acid (1), an antibiotic active against Gram‐negative and Gram‐positive bacteria, was synthesized starting from dehydroabietic acid (2) or abietic acid (26). The terpene ring system was functionalized and a Barton reaction used to oxidize Me(20). The intermediates of this photochemical reaction were isolated and characterized.
Elektronentransfer und Ionenpaar‐Bildung. 40. Mitteilung. Einkristall‐Struktur von Bis(Natrium‐1,1′‐Biphenyl‐2‐thiolat‐Diglyme): Ein Zwischenprodukt der reduktiven Ringöffnung von Dibenzothiophen
Authors: Bock Hans , Arad Claudia , Näther Christian , Havlas Zdenek , Göbel Ilka , John Andreas , Kleine Markus 
Published: December 2004

Electron Transfer and Ion Pair Formation Single Crystal Structure of Bis(sodium 1,1′‐biphenyl‐2‐thiolate‐diglyme): An Intermediate in the Reductive Ring Opening of DibenzothiopheneOn Na‐metal reduction of dibenzothiophene, the five‐membered sulfur ring opens to form a colorless 1,1′‐biphenyl‐2‐thiolate sodium salt, which, according to its single‐crystal structure determination, is a dimer containing a four‐membered, twice diglyme‐solvated ring (diglyme···Na⊕⊖SR)2. Additional measurements provide the following information: cyclic voltammetry in aprotic MeCN solution shows one quasi‐reversible electron transfer at E = −2.58 V. The dibenzothiophene radical anion can be generated in aprotic THF solution at a K mirror and characterized by an 81‐line ESR spectrum and its simulation. This blue species is also the first UV/VIS detectable one before the solution changes via green (due to blue + yellow color mixing) to yellow, yielding across an isosbestic point a second and diamagnetic compound. All of the above results suggest a consecutive two‐electron reduction followed by an intersystem protonation, M + (e⊖) → M.⊖ (blue) + (e⊖) → (M⊖⊖, yellow?) + (H⊕) → MH⊖ (colorless), to yield the crystallized and structurally characterized reaction intermediate. The diglyme‐solvated sodium‐salt dimer provides a basis for a quantum‐chemical discussion of some facets of the most likely microscopic reduction pathway.
Bortrifluorid‐katalysierte Umsetzung von 3‐Amino‐2H‐azirinen mit Amiden: Bildung von 4,4‐disubstituierten 4H‐Imidazolen
Authors: Arnhold Franziska , Chaloupka Stanislav , Linden Anthony , Heimgartner Heinz 
Published: December 2004

Boron Trifluoride Catalyzed Reaction of 3‐Amino‐2H‐azirines and Amides: Formation of 4,4‐Disubstituted 4H‐ImidazolesReaction of trifluoroacetamide and 3‐amino‐2H‐azirines 1 in refluxing MeCN affords 4‐amino‐2‐(trifluoromethyl)‐4H‐imidazoles 5 in fair yields (Scheme 3). Less acidic amides do not react with 1 under similar conditions. Therefore, a procedure involving BF3‐catalysis has been elaborated: the aminoazirine 1 in CH2Cl2 at −78° is treated with BF3 · Et2O and then with a solution of the sodium salt of an amide in THF, prepared by addition of sodium hexamethyldisilazane at −78°. The 4H‐imidazoles of type 5 are formed in ca. 50% yield (Scheme 4). Reaction mechanisms for this ring enlargement of 1 are proposed in Schemes 5 and 6.
Lacton‐Bildung durch ringerweiternde Fragmentierung von Epoxycyclodecanon‐Derivaten
Authors: Stojanova Diana S. , Hesse Manfred 
Published: December 2004

Lactones from Epoxycyclodecanone Derivatives by Ring Enlargement Involving Fragmentation ReactionsA stereospecific ring‐enlargement reaction of alkyl esters of 2,3‐epoxy‐1‐(3‐hydroxypropyl)‐10‐oxocyclo‐decanecarboxylic‐acid derivatives is described, involving Grob fragmentation of in situ formed hemiacetals. The assignment of the relative configuration of the starting materials was accomplished on the basis of 1H‐NMR data. The rearrangement of the epoxides 9 and 10 (with cis‐orientation of the ester group and the epoxide ring, Scheme 1) gives the lactone 15 as the single and as the major product, respectively, with (Z)‐configuration of the newly formed CC bond. A concerted reaction mechanism is assumed. The formation of a small amount of 12 from 10 is probably due to a competitive two‐step carbanion pathway. The reaction of the diastereoisomers 7 and 8 leads to the lactones 11 and 12, respectively, as the only ring‐enlargement products (Scheme 1), with (E)‐configuration of the newly formed CC bond. On the basis of our results, we cannot distinguish in this case between a concerted and a two‐step carbanion mechanism. This type of reaction takes place only in the presence of an ester group; no ring enlargement was detected in case of compound 20 (Scheme 3), which is the de(alkoxycarbonyl) derivative of 9. The eliminative opening of the epoxide ring in the epoxylactone 17 affords 11 as the single product (Scheme 2). A carbanion mechanism was assumed for this reaction.
Kupfer(II)‐chlorid‐katalysierte ‘Carben‐Dimerisierung’ von 1‐Halogeno‐1‐Lithiocyclopropanen: Ein einfacher Zugang zu Bi(cyclopropylidenen)
Authors: Loosli Thomas , Borer Markus , Kulakowska Iga , Minger Andrea , Neuenschwander Markus , Engel Peter 
Published: December 2004

Copper(II)‐Chloride Catalyzed ‘Carbene Dimerization’ of 1‐Halogeno‐1‐lithiocyclopropanes: A Simple Access to Bi(cyclopropylidenes)A series of 13 bi(cyclopropylidenes) 11 are prepared in a simple one‐pot reaction by halogeno‐lithio exchange between 1,1‐dibromocyclopropanes 1a–n and BuLi, in most cases at −95°, to give 1‐bromo‐1‐lithiocyclopropanes 2a–n, followed by treatment with CuCl2 at low temperature and a simple workup at room temperature (Scheme 3c and Table 1). The yields of bi(cyclopropylidenes) 11 strongly depend on reaction parameters, as explicitly shown for the conversion 1f →→ 11f (Tables 2–8). Mixed couplings between two different carbenoids are possible (Scheme 4), while diastereoselectivity of the active transition‐metal complex seems to be low. The structures of bi(cyclopropylidenes) 11 are confirmed by spectroscopic data as well as by X‐ray analysis of an isolated crystalline diastereoisomer of 11k (Fig. 1).
Novel Naamidine‐Type Alkaloids and Mixed‐Ligand Zinc(II) Complexes from a Calcareous Sponge, Leucetta sp., of the Coral Sea
Authors: Mancini Ines , Guella Graziano , Debitus Cécile , Pietra Francesco 
Published: December 2004

AbstractAs compounds from a calcareous sponge, Leucetta sp., of the Coral Sea, we isolated a series of novel naamidine‐type alkaloids, 6–10, which are oxidized at a single benzylic position. We also report on the first marine, mixed‐ligand metal complex 5 and on the first natural metal complexes 3 and 4 derived from classical naamidines, i.e., 1 and 2. The latter are also present in free form in the sponge.
Design, synthesis, and anti‐ Trypanosoma cruzi evaluation of a new class of cell‐growth inhibitors structurally related to Fenoxycarb
Authors: Schvartzapel Andrea J. , Fichera Laura , Esteva Mónica , Rodriguez Juan B. , Gros Eduardo G. 
Published: December 2004

AbstractSeveral compounds, structurally related to the insect‐growth regulator Fenoxycarb (1), were designed and synthesized. These compounds were tested as growth inhibitors of Trypanosoma cruzi cells (epimastigotes). Compounds 6, 16, 18, and 22 were very active against T. cruzi making them promising good candidates either for blood‐bank sterilization of Chagas'‐disease surveillance, while compounds 11, 12, 13, and 19 showed a moderate degree of activity.
Azetidin‐3‐ones from (S)‐α‐Amino Acids and Their Reactions with Nucleophiles: Preparation of some azetidine‐containing amino‐alcohol and amino‐acid derivatives
Authors: Podlech Joachim , Seebach Dieter 
Published: December 2004

AbstractThe reactions of azetidin‐3‐ones 6–10, readily available from the amino acids L‐alanine, L‐phenylalanine, L‐valine, L‐lysine, and L‐aspartic acid, via the corresponding diazo ketones, with nucleophilic reagents such as complex hydrides, Grignard compounds, an ester enolate, and a Wittig ylide give the expected products 11–19 in good yields and mostly in high diastereoselectivities. New amino‐alcohol, γ‐amino‐ and γ‐amino‐β‐hydroxy‐carboxylic‐acid derivatives of known configurations are thus available.
Metal Complexes with Macrocyclic Ligands. Part XL. Syntheses and silver(I) complexes of mono‐ and disubstituted dithiadiazamacrocycles
Authors: Riesen Pascale C. , Kaden Thomas A. 
Published: December 2004

AbstractA series of N2S2‐macrocycles with ring sizes varying between 12 and 16, as well as two 12‐membered N2S2‐rings with a pendant carboxylic and amino group, respectively, were synthesized. Their complexation properties towards Ag+ were studied by pH titrations and by potentiometry with a silver electrode. The observation that 1:1 ([AgLH2]3+, [AgLH]2+, [AgL]+) and 1:2 species ([AgL2H2]3+, [AgL2H]2+, [AgL2]+) were formed is interpreted by postulating that Ag+ can bind either to the S‐donors only, or to both the N‐ and S‐atoms. The most stable complex [AgL]+ in the series of the nonfunctionalized macrocycles was found for the 12‐membered N2S2‐ring 3. The stability of it increased when an additional donor group was introduced into the side chain. The highest formation constant (logβ110 = 14.43(1)) was obtained with the 12‐membered ring 12 carrying the ethanamine side chain. In view of a radiochemical application, all Ag+ complexes were tested in blood serum for their stability, but were not stable enough against transmetallation.
Electrochemistry of Mono‐ through Hexakis‐adducts of C60
Authors: Boudon Corinne , Gisselbrecht Jean‐Paul , Gross Maurice , Isaacs Lyle , Anderson Harry L. , Faust Rüdiger , Diederich François 
Published: December 2004

AbstractThe first systematic electrochemical study by cyclic voltammetry (CV) and rotating‐disk electrode (RDE) of the changes in redox properties of covalent fullerene derivatives (2–11) as a function of increasing number of addends is reported. Dialkynylmethanofullerenes 2–4 undergo multiple, fullerene‐centered reduction steps at slightly more negative potentials than C60 (1; see Table and Fig. 1). The two C‐spheres in the dumbbell‐shaped dimeric fullerene derivative 4 show independent, identical redox characteristics. This highlights the insulating character of the sp3‐C‐atoms in methanofullerenes which prevent through‐bond communication of substituent effects from the methano bridge to the fullerene sphere. In the series of mono‐ through hexakis‐adducts 5–11, formed by tether‐directed remote functionalization, reductions become increasingly difficult and more irreversible with increasing number of addends (see Table and Fig. 2). Whereas, in 0.1M Bu4NPF6/CH2Cl2, the first reduction of mono‐adduct 5 occurs reversibly at −1.06 V vs. the ferrocene/ferricinium couple (Fc/Fc+), hexakis‐adduct 11 is reduced irreversibly only at − 1.87 V. Hence, with incremental functionalization of the fullerene, the LUMO of the remaining conjugated framework is raised in energy. Reduction potentials are also dependent on the relative spatial disposition of the addends on the surface of the fullerene sphere. Observed UV/VIS spectral changes and changes in the chemical reactivity along the series 5–11 are in accord with the results of electrochemical measurements. Further, with increasing number of addends, the oxidation of derivatives 5–11 becomes more reversible. Whereas oxidations are increasingly facilitated upon going from mono‐adduct 5 (+1.22 V) to tris‐adduct 7 (+0.90 V), they occur at nearly the same potential (+0.95 to +0.99 V) in the higher adducts 8–11. This indicates that the oxidations occur in these compounds at a common sub‐structural element, for which a ‘cubic’ cyclophane is proposed (see Fig. 3). This sub‐structure is fully developed in hexakis‐adduct 11.