Synthesis of an Isotopically Isomeric Mixture of 1,4,6,8-Tetramethyl[13C2]azulene and Its Thermal Reaction with Dimethyl Acetylenedicarboxylate

Sodium [1,3-¹³C₂]cyclopentadienide in tetrahydrofuran (THF) has been prepared from the corresponding labelled [¹³C₂]cyclopentadiene which was synthesized from ¹³CO₂ and (chloromethyl)trimethylsilane (cf. Scheme 10) according to an established procedure. It could be shown that the acetate pyrolysis of cis-cyclopentane-1,2-diyl diacetate (cis- 22 ) at 550 ± 5° under reduced pressure (60 Torr) gives five times as much cyclopentadiene as trans- 22 . The reaction of sodium [1,3-¹³C₂]cyclopentadienide with 2,4,6-trimethylpyrylium tetrafluoroborate in THF leads to the formation of the statistically expected 2:2:1 mixture of 4,6,8-trimethyl[1,3a-¹³C₂], -[2,3a-¹³C₂]-, and -[1,3-¹³C₂]azulene ( 20 ; cf. Scheme 7 and Fig. 1). Formylation and reduction of the 2:2:1 mixture [¹³C₂]- 20 results in the formation of a 1:1:1:1:1 mixture of 1,4,6,8-tetramethyl[1,3-¹³C₂]-, -[1,3a-¹³C₂]-, -[2,3a-¹³C₂]-, -[2,8a-¹³C₂]-, and -[3,8a-¹³C₂]azulene ( 5 ; cf. Scheme 8 and Fig. 2). The measured ²J(¹³C, ¹³C) values of [¹³C₂]- 20 and [¹³C₂]- 5 are listed in Tables 1 and 2. Thermal reaction of the 1:1:1:1:1 mixture [¹³C₂]- 5 with the four-fold amount of dimethyl acetylenedicarboxylate (ADM) at 200° in tetralin (cf. Scheme 2) gave 5,6,8,10-tetramethyl-[¹³C₂]heptalene-1,2-dicarboxylate ([¹³C₂]- 6a ; 22%), its double-bond-shifted (DBS) isomer [¹³C₂]- 6b (19%), and the corresponding azulene-1,2-dicarboxylate 7 (18%). The isotopically isomeric mixture of [¹³C₂]- 6a showed no ¹J(¹³C,¹³C) at C(5) (cf. Fig. 3). This finding is in agreement with the fact that the expected primary tricyclic intermediate [7,11-¹³C₂]- 8 exhibits at 200° in tetralin only cleavage of the C(1)? C(10) bond and formation of a C(7)? C(10) bond (cf. Schemes 6 and 9), but no cleavage of the C(1)? C(11) bond and formation of a C(7)? C(11) bond. The limits of detection of the applied method is ≥96% for the observed process, i.e., [1,3a-¹³C₂]- 5 + ADM→ [7,11-¹³C₂]- 8 →[1,6-¹³C₂]- 9 →[5,10a-¹³C₂]- 6a (cf. Scheme 6).     

Novel heterocyclic systems. Part 27. The synthesis of various diazathianthrenes and the discrimination of isomeric structures using 13C-NMR and lanthanide induced shift data

Syntheses of the previously unknown 1,7-1,8- and 1,9-diazathianthrenes are reported. The former two systems were prepared via the condensation of the dianion of 2,3-dimercaptopyridine with 3-chloro-4-nitropyridine 1-oxide while the latter employed 2-chloro-3-nitropyridine. The preparation of the 1,9-diazathianthrene also led to the formation of the previously reported 1,6-diazathianthrene as a by-product in a 22% yield. The new ring systems were characterized by a combination of ¹³C nmr and ¹H lanthanide-induced shifts using Eu(fod)₃.     

Synthesis and nmr spectra of the six isomeric thieno[c]-fused 1,7- and 1,8-naphthyridines

Through the use of Pd(0)-catalyzed coupling between 2- and 4-formyl-3-thiopheneboronic acid and 4-iodo-3-aminopyridine ( 1 ) and 3-bromo-2-aminopyridine, convenient one-pot procedures for the preparation of thieno[2,3-c]-1,7-naphthyridine ( 2 ), thieno[3,4-c]-1,7-naphthyridine ( 3 ), thieno[2,3-c]-1,8-naphthyridine ( 6 ) and thieno[3,4-c]-1,8-naphthyridine ( 7 ) have been developed. Thieno[3,2-c]-1,7-naphthyridine ( 4 ) and thieno[3,2-c]-1,8-naphthyridine ( 8 ) were obtained through the coupling of 2-tri-n-butylstannyl-3-thiophenaldehyde with 2,2-dimethyl-N-(4-iodo-3-pyridinyl)propanamide and 3-bromo-2-acetamidopyridine ( 1 ). The yield of 8 was further increased when copper(II) oxide was used as the co-reagent. The ¹³C nmr spectra of the six isomeric thieno[c]-fused 1,7- and 1,6-naphthyridines are discussed.     

Linear aliphatic polysulfides: Synthesis and characterization

Binary condensation copolymers of 1,2-ethane dithiol and 1,3-propane dibromide, 1,4-butane dibromide, and 1,6-hexane dibromide were prepared. Yields ranged from 55 to 89% with molecular weights of 1–2 × 10⁴ Daltons. The polymers were synthesized via an S_N2 process with and without the presence of water. The polymers were characterized by DSC, viscosity, FT-IR, and ¹H-and ¹³C-NMR spectra.     

In quest of reversibility of Friedel-Crafts acyl rearrangements in the pyrene series

Friedel-Crafts acyl rearrangements in PPA of diacetylpyrenes (80–120 °C), dibenzoylpyrenes (80–200 °C), and bis(4-flurobenzoyl)pyrenes (80–120 °C) and Scholl reactions in AlCl₃/NaCl of dibenzoylpyrenes (140–200 °C) have been studied. The substrates were 1-AcPY, 2-AcPY, 1,3-Ac₂PY, 1,6-Ac₂PY, 1,8-Ac₂PY, 2,7-Ac₂PY, 1-BzPY, 1,6-Bz₂PY, 1,8-Bz₂PY, 1-4FBzPY, 1,6-4FBz₂PY, 1,8-4FBz₂PY. The mixtures of pyrene, 1-AcPY, 2-AcPY, 1,3-Ac₂PY, 1,6-Ac₂PY, 1,8-Ac₂PY, and 2,7-Ac₂PY were separated by HPLC. The following reversible intermolecular isomerizations were established: 1,6-Ac₂PY ? 1,8-Ac₂PY, 1,6-Bz₂PY ? 1,8-Bz₂PY, and 1,6-4'FBz₂PY ? 1,8-4'FBz₂PY, albeit not in high yields. The results substantiate Gore’s 1955 proposition that “The Friedel–Crafts acylation reaction of reactive aromatic hydrocarbons is a reversible process.” The isomerizations reported here differ from the few previously reported completely reversible intramolecular Friedel-Crafts acyl rearrangements. At ≥ 140 °C, in PPA and in AlCl₃/NaCl, 1,6-Bz₂PY and 1,8-Bz₂PY underwent a highly regioselective double Scholl reaction to give pyranthrone (3) and deacylations to 1-BzPy (and pyrene), followed by mono-Scholl reactions to give 8H-dibenzo[def,qr]chrysen-8-one (1), and 11H-indeno[2,1-a]pyren-11-one (2). The formation of 3 and not the expected tribenzo[a,ghi,o]perylene-7,16-dione (4) from 1,8-Bz₂PY indicates that 1,8-Bz₂PY has first undergone isomerization to 1,6-Bz₂PY. The present study confirms the linkage between Friedel-Crafts acyl rearrangements and the Scholl reaction.

     

Synthesis and NMR characterization of a novel heterologue of pyrene: The naphtho[1,8-bc;4,5-b'c']dipyran (1,8-dioxapyrene)

1,8-Dioxapyrene, a novel unsubstituted dioxa-analog of pyrene was synthesized from 4-methoxy-1-naphthol in a ten-step reaction involving two peri-heterocyclizations. ¹H and ¹³C nmr indicated a disruption of extended delocalization of π electrons, like that observed with the 1,6-isomer.     

1,8‐Bis[(dimethoxy)phosphino]naphthalene: A New Bis‐phosphonite Ligand with a Rigid C3‐Backbone and Unexpected Reaction Chemistry

1,8‐Bis[(diethylamino)phosphino]naphthalene ( 1 ) reacted with dry methanol in dichloromethane to form the new bis‐phosphonite ligand 1,8‐bis[(dimethoxy)phosphino]naphthalene (dmeopn, 2 ). By oxidation of 2 with H₂O₂ · (H₂N)₂C(:O) the corresponding bis‐phosphonate, 1,8‐bis[(dimethoxy)phosphoryl]naphthalene ( 3 ), was obtained quantitatively. Reaction of 3 with phosphorus trichloride unexpectedly furnished a 2.4 : 1 mixture of the bis‐phosphonate anhydrides rac‐ and meso‐1,3‐dimethoxy‐1,3‐dioxo‐2,3‐dihydro‐1,3‐diphospha‐2‐oxaphenalene (rac‐ 4 and meso‐ 4 ) from which rac‐ 4 could be fractionally crystallised. The bis‐phosphonite 2 behaved as a normal bidentate chelate ligand towards Mo⁰ and Pd^II, and furnished the complexes [(dmeopn)Mo(CO)₄] ( 5 ) and [(dmeopn)PdCl₂] ( 6 ) when treated with [(nor)Mo(CO)₄] or [(cod)PdCl₂] (nor = norbornadiene, cod = cycloocta‐1,8‐diene). Attempts to prepare 1,8‐diphosphinonaphthalene ( 7 ) by reducing 2 or 3 with LiAlH₄ or LiAlH₄/TMSCl (1 : 1) (TMSCl = trimethyl chlorosilane) in THF led to inseparable mixtures of phosphorus‐containing products. Compounds 2 – 6 were characterised by ¹H‐, ¹³C‐, and ³¹P‐NMR spectroscopy, IR spectroscopy, mass spectrometry and elemental analysis. X‐ray crystal structure analyses were carried out for the bis‐phosphonate anhydride rac‐ 4 and the palladium(II) complex 6 . The geometry of compound rac‐ 4 , in which the phosphorus atoms are connected by an oxygen atom, reveals a relief of strain from the bis‐phosphine 1 , whereas the 1,8‐P,P′‐naphthalenediyl group in 6 is surprisingly distorted; the P atoms are displaced from the naphthalene best plane by –46.7 and 54.5 pm.     

The assignment of the 1H and the 13C NMR chemical shifts of N-phenyl-2,4-dimethylbuta-1,3-diene-1,4-sultam

The assignment of the signals in the ¹³C and ¹H NMR spectra of N-phenyl-2,4-dimethylbuta-1,3-diene-1,4-sultam is difficult for the signal pairs C-2 and C-4, C-1 and C-3, (C-1)? H, (C-2)? CH₃ and (C-4)? CH₃. The ¹³C NMR spectrum recorded under gated decoupling conditions provide long-range couplings which make possible an unambiguous assignment of the ¹³C NMR signal pairs. Application of the ¹H CW off-resonance decoupling technique in recording the ¹³C NMR spectra enables the assignment information from the ¹³C NMR spectrum to be transferred to the ¹H NMR spectrum.     

A fluorescence “on–off” sensor for the highly selective and sensitive detection of Cu2+ ion

In an attempt to obtain a model of copper(II) ion-selective sensors, a new 1,8-naphthalimide-based fluorescence chemosensor, N-allylamine-4-[(E)-4-(([2-aminoethyl]imino)methyl) benzene-1,3-diol]-1,8-naphthalimide (NABN), was designed and synthesized. The sensor NABN is fully characterized by melting point analysis, fourier transform infrared spectra, Ultraviolet–visible (UV–vis) spectra, fluorescence spectra, ¹H NMR and ¹³C NMR spectroscopy, and mass spectrometry. NABN showed an unrivaled sensing behavior and an ardent selectivity toward copper(II) ion over other competitive metal ions tested in solution (N,N-Dimethylformamide (DMF)/Tris–HCl buffer, 1:1, v/v, pH = 7.2). The sensor showed a linear fluorescence quenching toward copper(II) ion in the range 0–50 μM, with a detection limit of 1.92 × 10⁻⁷ M estimated. Job's method indicated the formation of a 2:1 coordinative mode of the sensor with copper(II) ion with a high threshold of binding constant of 4 × 10¹² M⁻¹. Combining the above results, the quenching response of NABN toward Cu(II) ions could be ascribed to the strong, intrinsic paramagnetic behavior of Cu(II).     

Compounds with bridgehead nitrogen. 44—the conformational analysis of perhydropyrido[1,2-c] [1,3]thiazine

The 270 MHz NMR data on trans- and cis-(H-4a, H-7)-7-ethylperhydropyrido[1,2-c][1,3]thiazine show heavy conformational bias to the trans- and S-inside cis-fused conformations, respectively. Comparison of the ¹³C NMR spectra of these anancomeric systems with the ¹³C NMR spectrum of perhydropyrido[1,2-c][1,3]thiazine indicates a trans-?S-inside cis-conformational equilibrium for the latter compound in CDCl₃ at 25°C, containing ca 75% trans-fused conformer. The ¹³C NMR spectrum of perhydropyrido[1,2-c][1,3]-thiazine at ?75°C showed 64% trans-fused conformer and 36% S-inside cis-conformer.     

Reaction of tetracyanoethene with tricarbonyliron complexes of some substituted 7-methylenecycloheptatrienes and the subsequent isomerization of the initial addition products

An NMR study of tetracyanoethene (tcne) addition to substituted (η⁴-7-methylenecycloheptatriene)Fe(CO)₃ complexes shows that 1,3-addition is the dominant initial reaction. Subsequent isomerisation of these 1,3-adducts to 1,6- or 1,8-adducts is controlled by steric factors. Frontier orbital analyses allow concerted pathways to be identified for each observed addition and isomerisation. The crystal structure of the tcne adduct of (η⁴-7-phenylmethylenecycloheptatriene)Fe(CO)₃ establishes an exo geometry for the phenyl substituent.     

A dynamic nuclear magnetic resonance spectroscopic study of conformational properties of 1,3-dioxepane and 4,4,7,7-tetramethyl-1,3-dioxepane

The 251 MHz ¹H and the natural abundance 63.1 MHz ¹³C NMR spectra of 1,3-dioxepane (1) and 4,4,7,7-tetramethyl-1,3-dioxepane (2) have been investigated over the temperature range of 5 to ?180 °C. While the spectra of 1 show no dynamic NMR effect, compound 2 exists in solution as a 1:1 mixture of a symmetrical (C₂) twist-chair and its mirror image conformation. The free energy barrier for the conformational racemization of 2 is 43 kJ mol^?1 (10.3 kcal mol^?1). Interconversion paths between various conformations of 2 are discussed. Compound 1 is suggested to have a symmetrical (C₂) twist-chair conformation which is rapidly pseudorotating via a chair conformation to achieve a time averaged symmetry of C_2v, even at ?180 °C.     

Preparation and characterization of binuclear CuII complexes derived from diamines and dialdehydes

New macrocyclic complexes were synthesized by template reaction of 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane, 1,4-bis(2-carboxyaldehydephenoxy)butane or 1,3-bis(2-carboxyaldehydephenoxy)propane with 1,4-bis(2-aminophenoxy)butane, 1,3-bis(2-aminophenoxy)butane, 1,4-bis(4-chloro-2-aminophenoxy)butane or 1,3-bis(4-chloro-2-aminophenoxy)butane and Cu(NO₃)₂ ·?3H₂O or Cu(ClO₄)₂ ·?6H₂O, respectively. The complexes have been characterized by elemental analysis, IR, ¹H and ¹³C NMR, UV–Vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. All complexes are diamagnetic and binuclear.     

Structure elucidation of acetylation products of 2-acyl-1,3-indanediones by correlation of infrared spectral data

Summary 2-(1-Acetoxyalkylidene)- and 2-(1-acetoxybenzylidene)-1,3-indanediones (1a–1e) were proven to be the products of acetylation of 2-acyl-1,3-indanediones (2a–2e) by ketene using a detailed investigation and correlation analysis of infrared spectral data as well as¹H-NMR and¹³C-NMR spectra. Study by means of CNDO/2 and MMPI methods also demonstrates that the structure1 is more stable as the alternative one of 2-acyl-3-acetoxy-2-indene-1-ones (5). It was shown that the recently proposed general correlations v(C=O)_s vs. v(C=O)_as and v(C=O) vs. X⁺(R) as well as the mechanical anharmonicities of asymmetric C=O stretching vibration can be successfully used as a tool of structural diagnostics of cyclic 1,3-dicarbonyl compounds.

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Strukturaufklärung von Acetylierungsprodukten von 2-Acyl-1,3-indandionen mittels Korrelation von Infrarot-Daten

Zusammenfassung 2-(1-Acetoxyalkyliden)- und 2-(1-Acetoxybenzyliden)-1,3-indandione (1a–1e) wurden mittels einer detaillierten infrarot-spektroskopischen Untersuchung (IR-Korrelation) und¹H-NMR und¹³C-NMR Spektroskopie als Acetylierungsprodukte von 2-Acyl-1,3-indandionen (2a–2e) mit Keten nachgewiesen. CNDO/2- und MMPI-Rechnungen zeigten auch, daß Struktur1 stabiler ist, als die der alternativen 2-Acyl-3-acetoxy-2-inden-1-one5. Es wird gezeigt, daß die kürzlich vorgeschlagenen allgemeinen Korrelationen v(C=O)_s gengen v(C=O)_as und v(C=O) gegen X ⁺(R) und auch die mechanischen Anharmonizitäten der asymmetrischen C=O Streckschwingung erfolgreich als Werkzeug zur Strukturaufklärung cyclischer 1,3-Dicarbonyl-Verbindungen eingesetzt werden können.

     

NEW POLYMER SYNTHESES 106. POLYCARBONATES BY RING-OPENING POLYCONDENSATIONS OF TIN-CONTAINING MACROCYCLES WITH BISCHLOROFORMATES

2,2-Dibutyl-2-stanna-1,3-dioxepane (DSDOP) was polycon-densed with bisphenol-A bischloroformate (BABC) in bulk. Regardless of the reaction temperature and time only number average molecular weights (M_ns) around 8,000–11,000 were obtained. ¹³C NMR spectra proved that the isolated copoly-carbonates possessed a random sequence. MALDI-TOF spectra of the crude and of the fractionated samples revealed that all samples contained macrocyclic polycarbonates. DSDOP was also used as initiator for the macrocyclic polymerization of-cap-rolactone. The resulting cyclic polylactones were then polycon-densed with BABC in situ. M_ns in the range of 25,000–40,000 and M_ws in the range of 40,000–65,000 were found based on polystyrene calibrated GPC measurements. Similar results were obtained when 1,6-hexanediol bischloroformate was used as electrophilic reaction partner in the polycondensation step.     

Observation of steric hindrance in heteraferrocenophanes by carbon-13 NMR

The ¹³C NMR spectra of stereoisomeric trans- and cis-1,3-dimethyl-2-oxa[3](1, 1′)ferrocenophanes, 1,2,3-trithia[3](1, 1′)ferrocenophane and 1,3-dithia[3](1, 1′)ferrocenophane have been recorded and analysed. The presence of steric hindrance in some of these compounds was confirmed and the conformations of the molecules were determined.     

Trace determination of nitrated polycyclic aromatic hydrocarbons using liquid chromatography with on-line electrochemical reduction and fluorescence detection

An efficient clean-up procedure coupled with a high performance liquid chromatography (HPLC) with on-line electrochemical (EC) reduction and fluorescence detection (FLD) was developed to quantify nitrated polycyclic aromatic hydrocarbons (NPAHs) in the airborne particulate. In this process, NPAHs were extracted ultrasonically followed by analysis by using a reversed phase column with an aqueous eluent containing 70% aqueous acetonitrile and sodium monocholoroacetate as a buffer solution. The extraction efficiencies were above 83% for 1-nitropyrene and 1,3-dinitropyrene (1,3-DNP) 1,6-DNP, and 1,8-DNP, and calibration graphs were linear with very good correlation coefficients (r>0.999) and the detection limits were in the range of 1.0-2.2 pg for dinitropyrenes and nitropyrene. The proposed method provides a relatively simple and convenient procedure for determining the NPAHs samples in airborne particulate.     

Chain-ring-chain tautomerism in 2-aryl-substituted hexahydropyrimidines and 1H-2,3-dihydroperimidines. Does it appear?

A series of 2-aryl substituted hexahydropyrimidines and perimidines were synthesized from aromatic aldehydes and substituted 1,3-propanediamines or 1,8-naphthalenediamine. The ¹H and ¹³C NMR spectra showed that 2-arylperimidines and 2-aryl-4,4,6-trimethylhexahydropyrimidines exist exclusively in ring forms even in DMSO solutions, whereas 2-aryl-4-methylhexahydropyrimidines undergo chain-ring-chain tautomerism with a good linear correlation between the ring-chain equilibrium constants (log K, where K=[ring]/[chain]) and the Hammett-Brown σ⁺ parameters of the aromatic substituents. 4,4,6-Trimethylhexahydropyrimidines underwent complete and irreversible ring opening in CF₃COOH solutions giving two different chain forms.     

1,6‐ and 1,7‐naphthyridines III. 13C‐NMR analysis of some hydroxy derivatives

The ¹³C‐NMR spectra of some 1,6‐naphthyridines 2 and 1,7‐naphthyridines 3 , as well as those of N‐methyl derivatives 4 and 5 , were recorded and analyzed. Results in dimethyl‐d₆ sulfoxide and deuteriochlo‐roform provide useful data on intra and intermolecular hydrogen bonds.     

Oligosaccharide Analogues of Polysaccharides. Part 26

The anthraquinone derivatives T‐x‐x ( x = 2, 4, and 8), possessing two cellobiosyl, cellotetraosyl, and cellooctaosyl chains, respectively, C‐glycosidically bonded at C(1) and C(8) were synthesised as potential mimics of cellulose I. The anthraquinone template enforces a parallel orientation of the cellodextrin chains at a distance corresponding to the one between the crystallographically independent chains of cellulose I, and the ethynyl and buta‐1,3‐diynyl linker units ensure an appropriate phase shift between them. The H‐bonding of the T‐x‐x mimics was analysed and compared to the one of the mono‐chained analogues T‐x and of the known cellulose II mimics N‐x‐x and N‐x where one or two cellodextrin chains are O‐glycosidically bonded to naphthalene‐1,8‐diethanol, or to naphthalene‐1‐ethanol. The OH signals of T‐x and T‐x‐x in solution in (D₆)DMSO were assigned on the basis of DQFCOSY, HSQC, and TOCSY (only of T‐4, T‐4‐4 , and T‐8‐8 ) spectra and on a comparison with the spectra of N‐x and N‐x‐x. Hydrogen bonding was analysed on the basis of the chemical shift of OH groups and its temperature dependence, coupling constants, SIMPLE ¹H‐NMR experiments, and ROESY spectra. T‐4‐4 and T‐8‐8 in (D₆)DMSO appear to adopt a V‐shape arrangement of the cellosyl chains, avoiding inter‐chain H‐bond interactions. The well‐resolved solid‐state CP/MAS ¹³C‐NMR spectra of the mono‐chained T‐x ( x = 1, 2, 4, and 8) show that only T‐8 is a close mimic of cellulose II. While the solid‐state CP/MAS ¹³C‐NMR spectrum of the C₁‐symmetric diglucoside T‐1‐1 is well‐resolved, the spectra of T‐2‐2 and T‐4‐4 show broad signals, and that of T‐8‐8 is rather well resolved. The spectrum of T‐8‐8 resembles that of cellulose I_β. A comparison of the X‐ray powder‐diffraction spectra of T‐8‐8 and T‐8 with those of celluloses confirms that T‐8‐8 is a H‐bond mimic of cellulose I and T‐8 one of cellulose II. Surprisingly, there is little difference between the CP/MAS ¹³C‐NMR spectra of the acetyl protected mono‐chained C‐glycosylated anthraquinone derivatives A‐x and the double‐chained A‐x‐x ( x = 2, 4, and 8). The spectra of A‐4 and A‐4‐4 resemble strongly the one of cellulose triacetate I ( CTA I ). The (less well‐resolved) spectra of the cellooctaosides A‐8 and A‐8‐8 , however, resemble the one of CTA II . The similarity between the solid‐state CP/MAS ¹³C‐NMR spectra of A‐4 and A‐4‐4 to the one of CTA I , and of A‐8 and A‐8‐8 to the one of CTA II is opposite to the observations in the acetylated cellodextrin series. The mono‐chained A‐x cellulose triacetate mimics 21 ( A‐2 ), 32 ( A‐4 ), and 55 ( A‐8 ) were synthesised by Sonogashira coupling of the cellooligosyl‐ethynes 15, 28 , and 50 , followed by selective deacetylation. Complete deacetylation provided the corresponding T‐x mimics. The double‐chained A‐x‐x mimics 24 ( A‐2‐2 ), 35 ( A‐4‐4 ), and 58 ( A‐8‐8 ) were prepared from A‐x by triflation and Sonogashira coupling with the cellosyl‐buta‐1,3‐diynes 19, 31 , and 53 . Their deacetylation provided the corresponding T‐x‐x mimics 25, 36 , and 59 . The cellooligosyl‐ethynes and cellooligosyl‐buta‐1,3‐diynes required for the Sonogashira coupling were prepared by stepwise glycosylation of the partially O‐benzylated β‐cellobiosyl‐ethyne and β‐cellobiosyl‐buta‐1,3‐diyne 13 and 17 , respectively, with the cellobiosyl donor 2 and the cellohexaosyl donor 47 .