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Methylene-bridged resorcin[4]arene dimers were synthesized by the Sc(OTf)3-catalyzed hydroxymethylation of partially acetylated resorcin[4]arenes, and their preliminary complexation properties with tetraethylammonium ion were examined in CD3OD by 1H NMR spectroscopy. The dimers adopted a closed capsular conformation in this solvent and bound the guest molecule into their cavity.

A new type of isocoumarins (=1H-isochromen-1-ones=1H-2-benzopyran-1-ones), 4-substituted 3,4-dihydro-3-methoxyisocoumarins 2, can be obtained by a one-pot process from α-substituted 2-bromo-β-methoxystyrenes 1. Thus, lithium 2-(1-aryl(or methyl)-2-methoxyethenyl)benzoates are conveniently generated via the Br/Li exchange between 1 and BuLi, followed by the action of CO2 on the resulting α-substituted 2-lithio-β-methoxystyrenes. Upon treating with concentrated HCl at room temperature, these lithium benzoates undergo lactonization to provide the desired 3,4-dihydroisocoumarins 2 in relatively good yields.

An efficient method for the synthesis of 2-aryl-2,3-dihydro-3-sulfanyl-1H-isoindol-1-ones 1via Pummerer-type cyclization of N-aryl-2-(sulfinylmethyl)benzamides 2 is described. Thus, treatment of these sulfinyl-benzamides 2, easily prepared from 2-(bromomethyl)benzoates 3 in three steps, with Ac2O at ca. 100° resulted in the formation of the desired isoindolones 1 in generally good yields.

A novel method is reported for the synthesis of 9,9-disubstituted 9H-pyrrolo[1,2-a]indoles. Cyclization of 1-[2-(1-aryl(or methyl)ethenyl)phenyl]-1H-pyrroles, which can be easily prepared from 2-(1-aryl(or methyl)ethenyl)anilines, proceeds smoothly, in general, at 0° in the presence of a catalytic (or an equimolar) amount of HI in MeCN to provide the desired products.

The reaction of aryl(3-isocyanopyridin-4-yl)methanones 1, easily prepared from commercially available pyridin-3-amine, with aryl Grignard reagents gave, after aqueous workup, 2,3-diaryl-3H-pyrrolo[2,3-c]pyridin-3-ols 2. These rather unstable alcohols were O-acylated with Ac2O in pyridine in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP) to afford the corresponding 2,3-diaryl-3H-pyrrolo[2,3-c]pyridin-3-yl acetates 3 in relatively good yields.

An efficient one-pot procedure for the preparation of 4-substituted 4-alkoxy-1,4-dihydro-3,1-benzoxazine-2-thiones from 2-isothiocyanatobenzoates has been developed. Thus, 2-isothiocyanatobenzoates were reacted with organolithiums including lithium enolates of acetates and tertiary acetamides in THF at −78 °C to give the desired products in generally good yields.

An efficient method for the preparation of 2-substituted 4-aryl-4,5-dihydro-3,1-benzoxazepine derivatives under mild conditions has been developed. The reaction of 2-(2-aminophenyl)ethanols 1 with acid chlorides in the presence of excess Et3N in THF at room temperature gave the corresponding N-acylated intermediates 2, which were dehydrated by treatment with POCl3 to give 2-substituted 4-aryl-4,5-dihydro-3,1-benzoxazepines 3 in a one-pot reaction.

Thiomethylation of resorcin[4]arene using N,N-diisopropyl-2-aminoethanethiol hydrochloride and formaldehyde [1:4:4 molar ratio] carried out in methanol/acetic acid [1:1 v/v] at 60 °C produced monofunctionalized product 3 in 68% yield. The introduced substituent was intramolecularly self-included into the cavity. This self-inclusion reduced the reactivity of the aromatic rings and inhibited further functionalization.

A polydimethylsiloxane stamp was applied for the first time to the fabrication of n-channel thin-film transistors based on soluble small molecule organic semiconducting materials. The stamping method was found to facilitate film transfer onto a gate insulator surface irrespective of its surface free energy. We used [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) and C(60)-fused N-methylpyrrolidine-meta-dodecyl phenyl (C60MC12) as n-channel materials. The stamped thin-film transistors of C60MC12 achieved a high electron mobility of 0.39 cm(2)/(V s) and a current on-off ratio of 1 × 10(7). The mobility of the stamped C60MC12 thin-film transistors did not depend much on the surface free energy of the SiO(2) gate insulator with and without surface treatment using a silane-coupling reagent. In particular, the stamped C60MC12 thin-film transistor exhibited a relatively high mobility of 0.1 cm(2)/(V s) on a high energy surface of untreated SiO(2). In addition, a complementary inverter composed of an n-channel and a p-channel stamped thin-film transistor was demonstrated for the first time, which exhibits a maximum gain of 63 at a supply voltage of 50 V.

An efficient method for the synthesis of 2-aminoindole-3-carbonitriles and 2-aminoindole-3-carboxylates by the reaction of N-(2-iodophenyl)formamides with malononitrile and cyanoacetates, respectively, in the presence of a catalytic amount of copper(I) iodide using potassium carbonate as a base is reported.

An efficient synthesis of 3-alkyl-3,4-dihydro-4-thioxobenzoquinazolin-2(1H)-ones 3 has been accomplished in two steps and in satisfactory yields from 1-bromo-2-fluorobenzenes 1. Thus, the reaction of 1-fluoro-2-lithiobenzenes, generated by the Br/Li exchange between 1 and BuLi, with alkyl isothiocyanates, gives N-alkyl-2-fluorobenzothioamides 2, which, in turn, react with a series of isocyanates in the presence of NaH to give the desired products 3.

Two efficient methods for the preparation of 2-(2-sulfanyl-4H-3,1-benzothiazin-4-yl)acetic acid derivatives 3 under mild conditions have been developed. The first method is based on the reaction of 3-(2-isothiocyanatophenyl)prop-2-enoates 1a–1c with thiols in the presence of Et3N in THF at room temperature, leading to the corresponding dithiocarbamate intermediates 2, which underwent spontaneous cyclization at the same temperature by an attack of the S-atom at the prop-2-enoyl moiety in a 1,4-addition manner (Michael addition) to give 2-(2-sulfanyl-4H-3,1-benzothiazin-4-yl)acetates in one pot. The second method involves treatment of 3-(2-isothiocyanatophenyl)prop-2-enoic acid derivatives 1b–1d with Na2S leading to the formation of 2-(2-sodiosulfanyl-4H-3,1-benzothiazin-4-yl)acetic acid intermediates 5 by a similar addition/cyclization sequence, which are then allowed to react with alkyl or aryl halides to afford derivatives 3. 2-(2-Thioxo-4H-3,1-benzothiazin-4-yl)acetic acid derivatives 6 can be obtained by omitting the addition of halides.

An efficient one-pot method for the synthesis of 4-monosubstituted and 4,4-disubstituted 1,4-dihydro-3,1-benzoxazine-2-thiones has been developed. Treatment of 2-bromophenyl isothiocyantes with butyllithium in THF at −78 °C generates 2-lithiophenyl isothiocyanates, which are allowed to react with various carbonyl compounds, including aldehydes, ketones, and butanolide, to give the corresponding desired products in moderate to good yields.

A facile method for the synthesis of 3-substituted 3 H -indol-3-ols has been developed. Thus, 2-isocyanophenyl ketones are allowed to react with various Grignard reagents to give the corresponding desired indolol derivatives in generally fair to good yields. The formation of 3-aryl-2,3-dimethylindolin-3-ols by the reaction of 2-isocyanobenzophenones with 2 M amounts of methylmagnesium bromide is also reported.

A convenient method for the synthesis of 2,4,8-trisubstituted 1,7-naphthyridines 6 by the reaction of (E)-4-(1-aryl-2-methoxyethenyl)-3-isocyanopyridines 4, which could be easily prepared from commercially available 3-aminopyridine via aroylation of lithium (4-lithiopyridin-3-yl)pivalamide with N-methoxy-N-methylbenzamides, with excess organolithiums has been developed.

A new and facile method for the preparation of 2-substituted 2,3-dihydro-3,3-dimethyl-1H-isoindol-1-ones 3 and 3,3-disubstituted (E)-1-(arylimino)-1,3-dihydroisobenzofurans 6 has been developed. Thus, treatment of N-alkyl(or aryl)-2-(1-methylethen-1-yl)benzamides 2 with concentrated hydriodic acid (HI) in MeCN at room temperature afforded 3. Similar treatment of N-aryl-2-(1-phenylethen-1-yl)benzamide 5 with concentrated HI at 0 degrees afforded 6.

3-Aryl-1-thioacylindoles were prepared by treating α-aryl-2-isothiocyanato-β-methoxystyrenes with organolithiums or Grignard reagents, followed by hydriodic acid catalyzed cyclization of the resulting adducts. A one-pot synthesis of 1-thiocarbamoylindoles was achieved by hydriodic acid mediated cyclization of the corresponding thiourea intermediates, prepared from α-substituted 2-isothiocyanato-β-methoxystyrenes and secondary amines.

A facile method for the synthesis of 2,3-dihydro-3-methylidene-1H-isoindol-1-one and its derivatives carrying substituent(s) at C(5) and/or C(6) has been developed. The reaction of 2-formylbenzonitrile (1a) with dimethyloxosulfonium methylide, generated by the treatment of trimethylsulfoxonium iodide with NaH in DMSO/THF at 0°, resulted in the formation of 2,3-dihydro-3-methylidene-1H-isoindol-1-one (2a) in 77% yield. Similarly, six 2-formylbenzonitriles carrying substituent(s) at C(4) and/or C(5), i.e., 1b–1g, also gave the corresponding expected products 2b–2g in comparable yields.

An efficient method for the preparation of 2-(4 H-3,1-benzothiazin-4-yl)aceticacid derivatives and 2-(2-thioxo-1,2,3,4-tetrahydroquinazolin-4-yl)aceticacid derivatives has been developed. The reaction of 3-(2-isothiocyanatophenyl)propenoicacid derivatives with secondary amines in methanol at room temperature gavethe corresponding thiourea intermediates, which on heating at refluxtemperature cyclized by an attack of the sulfur atom on the propenoicmoiety in a 1,4-addition manner, to give 2-(2-dialkylamino-4 H-3,1-benzothiazin-4-yl)acetic acid derivativesin one pot. A similar sequence using primary amines in place ofsecondary amines afforded 2-[3-alkyl(or aryl)-2-thioxo-1,2,3,4-tetrahydroquinazolin-4-yl]aceticacid derivatives.

An efficient method for the preparation of 2,3-bis(arylamino)benzofurans and 2,3-bis(arylimino)-2,3-dihydrobenzofurans is described that is based on the reaction of 2-aryliminophenols with aryl isocyanides in the presence of a catalytic amount of boron trifluoride diethyl etherate. The reaction gives 2,3-bis(arylamino)benzofurans, some of which are transformed into 2,3-bis(arylimino)-2,3-dihydrobenzofurans by air oxidation, mostly during workup.

An efficient method for preparing 2-alkylsulfanyl-3H-4,5-dihydro-1,3-benzodiazepin-4-ones and 2-alkylsulfanyl-3H-4,5-dihydro-1,3-benzodiazepine-4-thiones under mild conditions has been developed. Thus, 2-(2-isocyanophenyl)acetamides and 2-(2-isocyanophenyl)thioacetamides, easily available from respective 1-isocyano-2-methylbenzenes, were converted into the corresponding isothiocyanates on treatment with sulfur in the presence of a catalytic amount of selenium, which were then reacted with an equimolar amount to sodium hydride to give 2-(sodiosulfanyl)-3H-4,5-dihydro-1,3-benzodiazepin-4-one and 2-(sodiosulfanyl)-3H-4,5-dihydro-1,3-benzodiazepine-4-thione intermediates, respectively. These intermediates were allowed to react with various alkyl halides to afford the desired benzodiazepinone or benzodiazepinethione derivatives in a one-pot reaction.

We have investigated self-assembled monolayer (SAM) treatment on SiO 2 gate insulator of poly(3-hexylthiophene) (P3HT) thin-film transistor (TFT), and demonstrated a correlation between mobility and surface free energy of the insulator. The device with lower surface free energy shows higher mobility. The docosyltrichlorosilane (DCTS)-treated device exhibits the best performance among the various SAM-treated devices examined. Field-effect mobility, on/off ratio and threshold voltage of the DCTS-treated P3HT TFT were 0.015 cm 2 /Vs, >10 5 and −14 V, respectively.

Four oxacalix[4]arene derivatives, in which 1,3-dinitrobenzene units and 1,3-di- tert -butylbenzene units are incorporated in alternating order, were synthesized by aromatic nucleophilic substitution. The introduction of the tert -butyl groups increased the stability of the macrocycles against nucleophilic C–O bond cleavage. X-ray crystal structure analyses reveal that the oxacalixarenes adopt an unsymmetrical 1,3-alternate conformation. The bulky substituents did not disturb the conjugation between the bridging oxygen atoms and the dinitrobenzene rings.

A convenient method for the preparation of 2-aryl(or methyl)sulfanylbenzo[b]thiophenes has been developed. Thus, aryl 2-aryl(or methyl)sulfanylmethylsulfanylphenyl ketones, easily prepared from readily available aryl 2-sulfanylphenyl ketones or 2-chloro-5-nitrophenyl phenyl ketone, are treated with LDA in 1,2-dimethoxyethane (DME) to give 3-aryl-2-aryl(or methyl)sulfanylmethylsulfanyl-2,3-dihydrobenzo[b]thiophen-3-ols, which in turn were dehydrated with thionyl chloride to afford 3-aryl-2-aryl(or methyl)sulfanylbenzo[b]thiophenes in reasonable overall yields.

The reaction of 2-(chloromethyl)phenyl isocyanides, readily available by dehydration of the respective N-[2-(chloromethyl)phenyl]formamides, with organolithiums produced 2-substituted indoles in satisfactory yields through addition of organolithiums to the isocyano carbon followed by intramolecular substitution reaction of the resulting imidoyl anion intermediates.

Oxygen- and sulfur-bridged calix[4]arenes have been synthesized by the nucleophilic aromatic substitution of 1,5-difluoro-2,4-dinitrobenzene with 4,6-diisopropylresorcinol or 4,6-diisopropyl-1,3-benzenedithiol. X-ray crystal structure analyses revealed that the oxacalix[4]arene 2 adopts an unsymmetrical 1,3-alternate conformation and that the dinitrobenzene rings strongly conjugate with the bridging oxygen atoms. On the other hand, the thiacalix[4]arene 3 adopts a heavily twisted unsymmetrical 1,3-alternate conformation, and the conjugation is very weak. In the 1H NMR spectrum (CDCl3, 30 °C), both compounds display a pair of diastereotopic methyl signals for the isopropyl groups in agreement with the frozen 1,3-alternate conformation on the NMR time scale. The free energies of activation ( Δ G 298 # ) of the macrocyclic inversion for 2 and 3 were determined to be 69.5 kJ mol−1 and 74.9 kJ mol−1, respectively, by variable temperature NMR spectroscopy.

The reaction of α-substituted 2-isocyanostyrenes, which could be readily prepared from commercially available 2-aminophenyl ketones or 2-aminobenzonitriles, with sulfur in the presence of a catalytic amount of selenium proceeded smoothly to give the corresponding 2-isothiocyanatestyrenes. The latter spontaneously underwent the electrocyclic reaction to afford 4-substituted quinoline-2(1H)-thiones in one-pot with isolated yields ranging from 37 to 91%.

An efficient two-step method for the synthesis of 1,3-diaryl-2-methoxyindenes from 1-(1-aryl-2-methoxyvinyl)-2-bromobenzenes has been developed. Thus, the reaction of 2-(1-aryl-2-methoxyvinyl)phenyllithiums, generated in situ by halogen–lithium exchange between 1-(1-aryl-2-methoxyvinyl)-2-bromobenzenes and butyllithium, with aromatic aldehydes gives aryl[2-(1-aryl-2-methoxyvinyl)phenyl]methanols, which in turn are treated with a catalytic amount of concentrated hydriodic acid to afford the corresponding 1,3-diaryl-2-methoxyindenes in reasonable yields.

3-Arylthieno[2,3-b]pyridines are synthesized in a short four-step sequence from readily available 2-bromopyridines. The final and key step of the reported method involves an iodine-mediated 5-endo cyclization of 3-(1-arylalkenyl)-2-[(1-phenylethyl)sulfanyl]pyridines.

An efficient method has been developed for the preparation of 3-acyl-2-(alkylsulfanyl)indoles and ethyl 2-(alkylsulfanyl)indole-3-carboxylates under mild conditions. (2-Iso-cyanophenyl)methyl ketones and ethyl 2-(2-isocyanophenyl)acetates were converted into the corresponding isothiocyanates by treatment with sulfur in the presence of a catalytic amount of selenium. The isothiocyanates were then treated with two equivalents of sodium hydride to form reactive disodium indol-1-ide-2-thiolate intermediates that were treated with alkyl halides to give the desired indole derivatives in a one-pot process. The method has been applied to the construction of three new indole-fused tricyclic structures by using α,ω-dibromoalkanes.

2-( 1-Alkoxyalkyl)-4-alkylidene-4H-3,1-benzoxazines are conveniently prepared by the reaction of 1-(2-isocyanophenyl)ethanones or l-(2-isocyanophenyl)propan-l-ones with a vinyl ether, such as 2-methoxypropene or ethyl vinyl ether, in the presence of a catalytic amount of(±)-camphor-10-sulfonic acid.

Tetranitroazacalix[4]arenes have been synthesized by the nucleophilic aromatic substitution of 1,5-difluoro-2,4-dinitrobenzene with 1,3-diaminobenzenes. An X-ray crystal structure analysis revealed that the azacalixarenes adopt a non-symmetrical 1,3-alternate conformation, and the dinitrobenzene rings strongly conjugate with the bridging nitrogen atoms. In the 1 H NMR spectrum (CDCl 3 , 30 °C), the tetraisopropyl derivative 3b displays a pair of diastereotopic methyl signals of the isopropyl groups in agreement with the frozen 1,3-alternate conformation on the NMR time scale. The free energy of activation ( Δ G 298 ≠ ) for the macrocyclic inversion was determined to be 87.5 kJ mol −1 by temperature-dependent NMR spectroscopy.

A simple method for synthesizing 1-aryl-4-hydroxy- N, N-dimethyl-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamideshas been developed. Thus, 3-(2-chloropyridin-3-yl)- N, N-di-methyl-3-oxopropanamide,easily prepared by treating ethyl 2-chloropyridine-3-carboxylatewith lithium enolate of N, N-dimeth-ylacetamide, smoothlyreacts with a range of aryl isocyanates in the presence of two molaramounts of sodium hydride to provide the desired products in moderateyields.

The thermal isomerization of anti to syn stereoisomers of oxacalix[4]arene bearing two methyl groups at the intra-annular distal positions was investigated by temperature-dependent NMR spectroscopy. The conversion followed a first-order kinetics, and very slowly proceeded at 473 K in nitrobenzene-d5 with a half-life of 7.2 h. The free energy of activation (ΔG≠ 139 kJ mol−1) is much higher than those for the ring inversion of related calix[4]arene derivatives.

An efficient preparation of (Z)-2-[quinazolin-4(3H)-ylidene]acetonitriles has been achieved in one pot by addition of 2-lithioacetonitrile to the cyano carbon of N-(2-cyanophenyl)alkanimidates, followed by intramolecular attack of the resulting imino anion on the imidate carbon with loss of alkoxide and subsequent tautomerization.

A facile two-step preparation of the title pyridothiazine derivatives starting from commercially available 2-chloro-6-methylpyridine-3-carbonitrile is described. The reaction of this nitrile with magnesium enolates of tertiary acetamides affords ( Z)-3-amino-3-(2-chloro-6-methylpyridin-3-yl)propenamide derivatives, which in turn are allowed to react with isothiocyanates in the presence of sodium hydride to give the desired products in satisfactory yields.

A new and simple method for the preparation of 1-aminonaphthalene-2-carbonitrile derivatives has been developed. When 2-(1-arylethenyl)benzonitriles are treated with 2-lithioacetonitrile, 1 -amino-4-aryl-3,4-dihydronaphthalene-2-carbonitriles are obtained in good yields. The reaction of 2-(1-aryl-2-methoxyethenyl)benzonitriles with 2-lithioacetonitrile leads to the formation of l-amino-4-arylnaphthalene-2-carbonitriles in fair-to-good yields.

The reactions of α-substituted 2-lithio-β-methoxystyrenes, generated in situ by bromine-lithium exchange between α-substituted 2-bromo-β-methoxystyrenes and butyllithium in diethyl ether at 0 °C, with carbonyl compounds afforded α-substituted 2-(β-methoxyvinyl)benzyl alcohols, which were treated with a catalytic amount of concentrated hydriodic acid to give 4-substituted iso-chromenes (1 H-2-benzopyrans) in reasonable yields.

A new and convenient method for the preparation of 3-substituted benzo[b]thiophenes was developed. α-Substituted 2-(1-phenylethylthio)styrenes, which could easily be prepared from 2-mercaptophenyl ...

Efficient methods have been developed for the preparation of 1(3H)-imino-2-benzothiophene and 1-imino-1H-2-benzothiopyran derivatives. Treatment of secondary o-(vinyl)thiobenzamide derivatives with...

An efficient method to prepare ABAC-type oxacalix[4]arenes by a ‘3+1’ fragment synthesis and their CsF-catalyzed disproportionation producing an equilibrium mixture of three oxacalix[4]arenes are described.

( Z)-2-(2-Acetyl-2 H-isoquinolin-1-ylidene)acetamides have been synthesized from 2-vinylbenzonitrile derivatives in three steps. The key step involves the iodine-mediated 6- ENDO cyclization of ( Z)-3-acetylamino-3-(2-vinylphenyl)propenamides, which are prepared by the coupling of 2-vinylbenzonitriles with magnesium enolates of tertiary amides followed by N-acetylation.

The host–guest interaction of C-methylresorcin[4]arene and its derivative having four tert-butylsulfanylmethyl groups at the extra-annular positions was studied by 1 H NMR spectroscopy in CD3OD. Based on the association constants (Ka) and the complexation-induced NMR shifts (CIS), it was concluded that the bulky substituents create a deep cavity with a narrow entrance and improve the size and shape selectivity.

A convenient synthetic method for 1-aryl-1H-indole derivatives has been developed. 2-(Arylamino)-α-methylstyrene derivatives were treated with iodine in the presence of sodium hydrogencarbonate to ...

A new and simple method for the preparation of 3,3-disubstituted isoindolin-1-ones from α-substituted 2-bromostyrenes is described. Construction of the isoindolin-1-one skeleton was accomplished by treating α-substituted secondary 2-vinylbenzamides, easily obtainable from the reaction of α-substituted 2-lithiostyrenes with isocyanates, with iodine to afford 3-substituted 3-iodomethyl-isoindolin-1-ones.

A simple and efficient synthesis of isoquinoline and 3,4-dihydroisoquinoline derivatives is described. 1-Alkyl(or aryl)isoquinoline and 1-isoquinolinamine derivatives were obtained by intramolecular cyclization of 2-(2-methoxyethenyl)benzonitriles initiated by the addition of alkyl(or aryl)lithiums and lithium dialkylamides to the nitrile carbons, respectively. Synthesis of 4-aryl-3,4-dihydroisoquinolines was achieved by reactions of 2-(l-arylethenyl)benzonitriles with organolithiums, followed by aqueous workup. Treatment of the reaction mixtures with electrophiles prior to aqueous workup allowed the synthesis of 4,4-disubstituted 3,4-dihydroisoquinolines.

The nucleophilic aromatic substitution of 1,5-difluoro-2,4-dinitrobenzene with 2-propylresorcinol in Et3N/CH3CN produces a mixture of syn and anti conformers of the cyclic tetramer and the cyclic hexamer with a kinetically controlled product distribution. Moreover, the reaction in DMF was catalyzed by CsF to also produce a mixture of these cyclic oligomers. In this case, however, the C–O bond is cleaved by the fluoride ion and the cyclization reaction is reversible; therefore, in the presence of excess CsF, the thermodynamically favored product (syn-isomer of cyclic tetramer) is obtained as the major product. The structures of the two conformational isomers of cyclic tetramers were determined by X-ray crystallography.

The cyclocondensation of 1,3-dialkoxybenzenes with 1,3,5-trioxane was catalyzed by Sc(OTf)3 to produce resorcin[4]arene octaalkyl ethers as the major products. In addition, ‘confused’ resorcin[4]arene octaalkyl ethers bearing one alkoxy group at the intra-annular position were obtained as the minor products. The variable temperature 1H NMR spectroscopy showed that the alkoxy group at the intra-annular position cannot pass through the macrocyclic annulus, indicating a rigid molecular framework. The structure of the ethoxy derivative of the confused resorcin[4]arene was determined by X-ray crystallography.