Anhydride Intermediate Research Articles

Trimethylsilyldiazomethane in the preparation of diazoketones via mixed anhydride and coupling reagent methods: a new approach to the Arndt–Eistert synthesis

Reaction of trimethylsilyldiazomethane with a mixed anhydride derived from a carboxylic acid by the action of ethyl chloroformate, yields the corresponding diazoketone in high yield. Subsequent Wolff rearrangement of the diazoketone leads to the homologated ester. Reaction of trimethylsilyldiazomethane with carboxylic acid–dicyclohexylcarbodiimide mixtures leads to the formation of diazoketone and trimethylsilylmethyl ester in equimolar ratio via an acid anhydride intermediate. The N-hydroxysuccinimide ester of the acid does not react with trimethylsilyldiazomethane or with its more reactive lithiated derivative.

IR spectroscopy study of cyclic anhydride as intermediate for ester crosslinking of cotton cellulose by polycarboxylic acids. V. Comparison of 1,2,4‐butanetricarboxylic acid and 1,2,3‐propanetricarboxylic acid

AbstractIn recent years extensive efforts have been made to use multifunctional carboxylic acids as formaldehyde‐free crosslinking agents for cotton to replace the traditional formaldehyde‐based N‐methylol reagents. In our previous research we found that a polycarboxylic acid esterifies cellulose through the formation of a five‐membered cyclic anhydride intermediate by dehydration of two adjacent carboxyl groups. In this research we used Fourier transform IR (FTIR) spectroscopy to study the formation of cyclic anhydride intermediates and crosslinking of cotton by 1,2,4‐butanetricarboxylic acid (BTA) and 1,2,3‐propanetricarboxylic acid (PCA). BTA and PCA form five‐membered cyclic anhydrides in the same temperature range. Both acids form the anhydrides at lower temperatures when a catalyst is present. When an acid molecule is bonded to cotton through an ester linkage, only PCA is able to form a second anhydride intermediate. We found that PCA is a more effective crosslinking agent, and it imparts higher levels of wrinkle resistance to the cotton fabric than BTA. Therefore, the formation of a five‐membered cyclic anhydride by a polycarboxylic acid accelerates the esterification of cotton by the acid. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2142–2150, 2001

FTIR Spectroscopy Study of Ester Crosslinking of Cotton Cellulose Catalyzed by Sodium Hypophosphite

In previous research, we found that sodium hypophosphite (NaH2PO2) reduces the temperature required for the formation of anhydride intermediates by polycarboxylic acids. We also found that a chemical reaction between the anhydride intermediate of 1,2,3,4-butanetetracarboxylic acid (BTCA) and NaH2PO2 takes place when the temperature rises above 200°C. In this research, we use Fourier transform infrared (FTIR) spectroscopy and thermal analysis to confirm that NaH2PO2 reacts with cis-1,2-cyclohexanedicarboxylic anhydride (CHDN) at temperatures above 170°C. NaH2PO2 catalyzes the formation of the cyclic anhydride intermediate by 3-butene-1,2,3-tricarboxylic acid (BTTA) on cotton. In the presence of NaH2PO2, BTTA forms a five-membered cyclic anhydride on cotton at temperatures as low as 120°C. However, no esterification takes place on the fabric at such temperatures. The data also indicate that NaH2PO2 reacts with the anhydride intermediate when the temperature rises above 180°C. We have found that esterification of cotton cellulose by BTTA takes place only when NaH2PO2 is present and the temperature is above 180°C. Therefore, the catalysis effects of NaH2PO2 for cotton esterification by BTTA are probably related to the reaction between NaH2PO2 and the anhydride intermediate.

Simple And Efficient Method For Synthesis Of Z-Boc-Amino Acid Amides Using P-Toluenesulphonyl Chloride

Amides of Z- and Boc protected amino acids have been prepared by using p-toluenesulphonyl chloride (TsCI) for the activation of carboxyl group. The resulting mixed carboxylic-sulphonic anhydride intermediate was treated in situ with an excess of 25 percent ammonia solution. All the amino acid amides prepared were obtained as crystalline solids in good yield and purity. Keywords: Boc-AMINO ACID, TOLUENESULPHONYL, luteinizing harmone, selective tosylation, layer chromatography, stirred solution, anhydrous sodium sulphate

A novel fluorescent coronenyl-phospholipid analogue for investigations of submicrosecond lipid fluctuations

A fluorescent phospholipid derivative, the 2′-(4-coronenylbutyric) ester of lyso-egg phosphatidylcholine, has been synthesized for use in studies of submicrosecond lipid dynamics. Synthesis of the phospholipid derivative involves Friedel–Crafts acylation of free coronene, followed by a Huang–Minlon reduction to yield the fatty-acyl derivative, 4-coronenylbutyric acid. Esterification of the carboxylic acid with lyso-phosphatidylcholine is achieved through a mixed anhydride intermediate. The resultant coronenyl-phospholipid adduct (Cor-PC) has been incorporated into sonicated unilamellar vesicles of dimyristoylphosphatidylcholine (DMPC) for dynamic lipid studies. Fluorescence quenching studies using potassium iodide, together with steady-state emission anisotropy (EA) measurements, confirm that the coronene moiety of the phospholipid adduct resides towards the head group interfacial region of the lipid bilayer. Unique properties of this new fluorescent phospholipid adduct are its long mean fluorescence lifetime ( τ av∼112 ns at 14°C), the planar symmetry of the fluorophore and its defined bilayer location. As a consequence, depolarizing motions of the coronene moiety target submicrosecond ‘gel–fluid’ lipid dynamics arising from a relatively narrow bilayer distribution. Our data suggest that the sensitivity of this new long-lived fluorescent phospholipid analogue to localized transverse submicrosecond lipid dynamics can provide important biological insights into varied processes including lipid–peptide interactions, bilayer fluidity gradients and passive ion transport.

Di-tert-butyl dicarbonate and 4-(dimethylamino)pyridine revisited. Their reactions with amines and alcohols

The reaction of BOC2O in the presence and absence of DMAP was examined with some amines, alcohols, diols, amino alcohols, and aminothiols. Often, unusual products were observed depending on the ratio of reagents, reaction time, polarity of solvent, pKa of alcohols, or type of amine (primary or secondary). In reactions of aliphatic alcohols with BOC2O/DMAP, we isolated for the first time carbonic-carbonic anhydride intermediates; this helps explain the formation of symmetrical carbonates in addition to the O-BOC products. In the case of secondary amines, we succeeded to isolate unstable carbamic-carbonic anhydride intermediates that in the presence of DMAP led to the final N-BOC product. The effect of N-methylimidazole in place of DMAP was also examined.

C6, C7, and C8 perfluoroalkyl-substituted phosphinic acids.

Reaction of red phosphorus with RfI in a 1:2 molar ratio at 230 degrees C led to the formation of a mixture of (Rf)2PI and (Rf)PI2 (Rf = C6F13, C7F15, C8F17) in about a 70:30 ratio, respectively. These mixtures were separated by vacuum distillation. (Rf)2PI (Rf = C6F13, C7F15) are yellow liquids whereas (C8F17)2PI is a yellow solid. Oxidation of (Rf)2PI with excess NO2 led to (Rf)2P(O)OH (Rf = C6F13, C7F15, C8F17) in > 90% isolated yields after aqueous hydrolysis of the anhydride intermediates. These highly fluorinated phosphinic acids are white solids with sharp melting points and are highly soluble in methyl sulfoxide (DMSO) and 1,1,2-trichlorotrifluoroethane. However, solubility in chloroform and methylene dichloride is low. These perfluoroalkylphosphinic acids were characterized by IR, NMR (1H, 19F, and 31P), and mass spectra and elemental analysis.

FT-IR and FT-raman spectroscopy study of the cyclic anhydride intermediates for the esterification of cellulose: III. Cyclic anhydrides formed by the isomers of cyclohexanedicarboxylic acid

Multifunctional carboxylic acids have been used as crosslinking agents for cotton and wood pulp cellulose. In our previous research, we found that a polycarboxylic acid esterifies cellulose through the formation of a 5-membered cyclic anhydride intermediate by the dehydration of two carboxyl groups. In this research, we studied the formation of cyclic anhydride intermediates by different isomers of cyclohexanedicarboxylic acid (CHA) so that we can elucidate the effects of molecular structure on the formation of the anhydride intermediates. We found that both cis-and trans-1,2-CHA form 5-membered anhydride intermediates when temperature reaches their melting points and that cis-1,2-CHA forms the cyclic anhydride at temperatures lower than does trans-1,2-CHA. 1,3-CHA forms 6-membered cyclic anhydride at temperatures much higher than its melting point. The formation of a 5-membered cyclic anhydride intermediates takes place at temperatures lower than that of a 6-membered anhydride. This is probably the main reason why those polycarboxylic acids with their carboxylic acid groups bonded to the adjacent carbons of the molecular backbones are more effective crosslinking agents for cellulose than those with their carboxylic groups bonded to the alternative carbons. No formation of cyclic anhydride was found for 1,4-CHA. The formation of a five-membered cyclic anhydride was accelerated by monosodium phosphate, which is used as a catalyst for the esterification of cotton cellulose by polycarboxylic acids.

FTIR Spectroscopy Study of the Formation of Cyclic Anhydride Intermediates of Polycarboxylic Acids Catalyzed by Sodium Hypophosphite

In recent years, extensive efforts have been made to find formaldehyde-free durable press finishes to replace the traditional formaldehyde-based N-methylol compounds. 1,2,3,4-Butane-tetracarboxylic acid (BTCA) has been the most efficient nonformaldehyde crosslinking agent for cotton, with sodium hypophosphite (NaH2PO2) being the most effective catalyst. In our previous research, we found that a polycarboxylic acid esterifies cellulose through the formation of a five-membered cyclic anhydride intermediate by the dehydration of two adjacent carboxyl groups. In this research, we use Fourier transform infrared spectroscopy (FTIR) to study the formation of cyclic anhydride intermediates by BTCA and poly(maleic acid) (PMA) with and without the presence of NaH2PO2. In the absence of NaH2PO2, BTCA forms the cyclic anhydride only when the temperature reaches the vicinity of its melting point. In the presence of NaH2PO2, however, the anhydride forms at much lower temperatures. We have found that NaH2PO2 weakens the hydrogen bonding between the carboxylic acid groups of BTCA, contributing to accelerated anhy dride formation at lower temperatures. Sodium hypophosphite also accelerates the for mation of the anhydride intermediates by polycarboxylic acids in an amorphous state. The FTIR spectroscopy data show that there is a chemical reaction between the anhydride intermediate and NaH2PO2 when the temperature climbs above 200°C.

Infrared spectroscopy studies of cyclic anhydrides as intermediates for ester crosslinking of cotton cellulose by polycarboxylic acids. IV.In situ free radical copolymerization of maleic acid and itaconic acid on cotton

Polycarboxylic acids have been used as crosslinking agents for cotton fabrics and paper to replace the traditional formaldehyde-based reagents. Previously, we found that a polycarboxylic acid esterifies cotton cellulose through the formation of a five-membered cyclic anhydride intermediate. Both maleic acid (MA) and itaconic acid (ITA) are extremely difficult to polymerize under conditions normally used for free radical polymerization. It has been reported in the literature that treatment of cotton fabric with a mixture of MA and ITA significantly improved wrinkle-resistance of the fabric. In this research, we investigated the in situ copolymerization of MA and ITA on cotton fabric. Fourier transform-infrared spectroscopy was used to study the anhydride carbonyl formed on the cotton fabric treated with the mixtures of MA and ITA. A redox titration technique also was applied to determine the quantity of alkene double bonds on the treated fabric. It was found that free radical copolymerization of MA and ITA does not occur on the fabric at elevated temperatures when potassium persulfate is present as an initiator. It does occur, however, when both potassium persulfate and sodium hypophosphite are present on the fabric. The in situ copolymerization on the cotton fabric probably is initiated by a reduction–oxidation system. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 327–336, 2000

Ft-Ir and Ft-Raman Spectroscopy Study of the Cyclic Anhydride Intermediates for the Esterification of Cellulose: Ii. Formation of Anhydrides Catalyzed By Sodium Hypophosphite

A five-membered cyclic anhydride is the reactive intermediate of polycarboxylic acids for esterifying cellulose. In our previous research, we found that polycarboxylic acids in a crystalline state start to form 5-membered cyclic carboxylic anhydrides when the temperature reaches the vicinity of their melting points, and that hydrogen bonding between carboxylic acid groups prevents the formation of the cyclic anhydride intermediates at lower temperatures. In this research, we studied the formation of cyclic anhydride intermediates by 1,2,3,4-butane-tetracarboxylic acid (BTCA) and itaconic acid (IA) in the presence of sodium hypophosphite (NaH 2 PO 2 ) ' We found that NaH 2 PO 2 weakens the hydrogen bonding between the carboxylic acid groups of BTCA. In the presence of NaH 2 PO 2 , BTCA forms the cyclic anhydride at temperatures significantly lower than its melting point. NaH 2 PO 2 also reduces the temperatures required for the formation of the anhydride intermediate of IA on cotton fabric. The catalysis for the formation of anhydride intermediates by NaH 2 PO 2 contributes to the acceleration of esterification of cotton cellulose by polycarboxylic acids.

Formation of five-membered cyclic anhydride intermediates by polycarboxylic acids: Thermal analysis and Fourier transform infrared spectroscopy

Butanetetracarboxylic acid (BTCA) has been used as the most effective nonformaldehyde crosslinking agent for cotton and wood pulp cellulose. Our previous research has indicated that a polycarboxylic acid esterifies cellulose in two steps: the formation of a five-membered cyclic anhydride intermediate by the dehydration of two adjacent carboxyl groups, and the reaction between cellulose and the anhydride intermediate to form an ester linkage. In this research, we investigated the formation of carboxylic anhydrides by BTCA and other polycarboxylic acids in powder forms, and as finishes applied to cotton fabric using thermal gravimetry, differential scanning calorimetry, and Fourier transform infrared spectroscopy. We found that BTCA and other polycarboxylic acids in powder forms start to form five-membered cyclic carboxylic anhydrides when the temperature reaches the vicinity of their melting points. The formation of carboxylic anhydride is accelerated above the melting points. We also found that BTCA forms anhydrides at lower temperatures when it is applied to cotton fabric as a finish. An increase in temperature increases both the amount of anhydride and the amount of ester formed on the cotton fabric. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2711–2718, 1998

FT-IR and FT-raman spectroscopy study of the cyclic anhydride intermediates for esterification of cellulose: I. Formation of anhydrides without a catalyst

In recent years, extensive efforts have been made to find nonformaldehyde durable press finishes to replace the traditional formaldehyde-based reagents for producing wrinkle-free cotton fabrics. 1,2,3,4-butanetetracarboxylic acid (BTCA) has been the most effective nonformaldehyde crosslinking agent. Our previous research has indicated that a polycarboxylic acid esterifies cellulose in two steps: the formation of a 5-membered cyclic anhydride intermediate by the dehydration of two adjacent carboxyl groups, and the reaction between cellulose and the anhydride intermediate to form an ester linkage. In this research, we used Fourier transform infrared and Fourier transform Raman spectroscopy to study the formation of cyclic anhydride intermediates by BTCA and other polycarboxylic acids without the presence of a catalyst. We found that BTCA and other polycarboxylic acids in a crystalline state start to form 5-membered cyclic carboxylic anhydrides when the temperature reaches the vicinity of their melting points with the exception of bifunctional acids, which form cyclic anhydrides at temperatures much higher than their melting points. Intermolecular hydrogen bonding between carboxylic acid groups prevents the formation of the cyclic anhydride intermediates at lower temperatures. We also found that polycarboxylic acids in an amorphous state form cyclic anhydrides at much lower temperatures.

Chemical Imidization Study by Spectroscopic Techniques. 2. Polyamic Acids

Chemical imidization of polyamic acid based on 1,5-diaminonaphthalene and a dianhydride was studied by UV−visible and FT-IR ATR techniques under various reaction conditions, such as polyamic acid concentration, solvent condition (dry vs humidity-exposed NMP), catalysts of tertiary amines with different degrees of steric crowding and base strength, and the concentration of the acetic anhydride and pyridine. With acetic anhydride and pyridine, the reaction was very similar to that of the model amic acids, with the simultaneous formation of bisimide groups and bisisoimide groups, followed by isomerization of bisisoimde groups to bisimide groups, which is very sensitive to the dryness of the solvent. The reaction with polymer films supported a similar trend. Chemical imidization seems to proceed by nucleophilic catalysis by tertiary amines, depending on the steric crowding as well as the base strength. Reducing steric crowding in the catalyst facilitates the formation of an acylammonium (or pyridinium) cation. The adjacent positive charge on the nitrogen makes the acyl group more electrophilic, making it easier for the amic acid anion to attack and form the mixed anhydride intermediate. The catalyst can further accelerate the reaction by deprotonating the mixed anhydride if the tertiary amine is not sterically crowded. The anionic mixed anhydride quickly cyclizes to give an imide group and an isoimide group. N-Methylpyrrolidine and triethylenediamine were found to make the reaction at least 50 times faster than pyridine, which is the most commonly used industrial catalyst, without changing the molecular weight and its distribution. This investigation shows that the acidity of the original amic acid and the acid produced during the reaction have a profound impact on the products and their ratio, which can be understood based on the mechanistic scheme proposed for the model amic acid. It is suggested that a careful choice of polyamic acid concentration, dehydrating agent, and catalyst may lead to greater control over the reaction and the polymer properties.

Nonformaldehyde Durable Press Finishing of Cotton Fabrics by Combining Citric Acid with Polymers of Maleic Acid

In our previous research, we investigated the use of two polymers of maleic acid, i.e., the homopolymer (PMA) and the terpolymer (TPMA), for crosslinking cotton cellulose. We found that PMA and TPMA were less effective than 1,2,3,4-butanetetracarboxylic acid (BTCA) due to the low mobility of the anhydride intermediates to access the cellulosic hydroxyl during a curing process. We found that the hydroxyl of citric acid (CA) hinders its esterification with cotton cellulose, and so is less effective than 1,2,3-propanetricar boxylic acid as a crosslinking agent for cotton. We also found that CA esterifies the anhydride intermediate of PMA or TPMA on the cotton fabric formed under curing con ditions. In this research, we observed a synergistic effect by combining PMA or TPMA with CA as co-crosslinking agents for cotton fabrics. The combination of TPMA/CA is more effective than the PMA/CA combination for imparting wrinkle resistance to the finished cotton fabrics. Cottons finished with the TPMA/CA combination show superior durable press performance, good laundering durability, and high fabric strength retention. The superior performance and cost effectiveness of this new finishing system makes it feasible as a replacement for formaldehyde-based durable press finishes.

Solid-state Stability of Human Insulin II. Effect of Water on Reactive Intermediate Partitioning in Lyophiles from pH 2–5 Solutions: Stabilization Against Covalent Dimer Formation

Previous studies have established that at low pH human insulin decomposition proceeds through a two-step mechanism involving rate-limiting intramolecular formation of a cyclic anhydride intermediate at the C-terminal AsnA21 followed by intermediate partitioning to various products, most notably desamido insulin and covalent dimers, in both aqueous solution and in the amorphous (lyophilized) solid state. This study examines the product distribution resulting from insulin degradation in lyophilized powders as a function of water content and the phase behavior of the solid (glassy versus rubbery) between pH 3 and 5. In amorphous solids at low water content (glassy state), the cyclic anhydride intermediate of insulin reacts predominantly with water to form deamidated insulin, whereas the intermolecular reaction with another insulin molecule to form a covalent dimer accounts for ≤15% of the total degradation. Increasing water content reduces the glass transition temperature of insulin to <35 °C, and covalent dimer formation becomes increasingly favored relative to deamidation. An increase in solid-state pH also favors dimerization as deprotonation of the terminal amino groups of insulin renders them more nucleophilic. Covalent dimerization was almost totally suppressed by incorporation into a glassy matrix of trehalose, which both minimizes molecular mobility and physically separates the insulin molecules. The kinetics and product distribution of human insulin in lyophilized powders between pH 3 and 5 illustrate the differential sensitivities of various solid-state reaction types to the effects of water activity and solid-phase behavior. The intramolecular cyclization at the AsnA21 position requires only short-range conformational flexibility and thus is only modestly restricted even in the glassy state. On the other hand, the competing bimolecular reactions involving either water or another molecule of insulin combining with the intermediate anhydride are dependent on molecular mobility of the reactants, in accord with predictions of free volume theory. In the glassy state, deamidation (reaction with water) is favored because of the restricted molecular mobility of proteins in rigid matrices. Increasing plasticization with increasing water content favors covalent aggregate formation because of the higher dependence of protein mobility on free volume within the solid matrix.

Ester Crosslinking of Cotton Fabric by Polymeric Carboxylic Acids and Citric Acid

Polycarboxylic acids appear to be the most promising nonformaldehyde durable press finishing agents to replace the traditional N-methylol reagents, 1,2,3,4-Butanetetracarboxylic acid (btca) is the most effective crosslinking agent among the acids investigated, but its exceedingly high cost has prevented its use in the textile industry on a commercial scale. In this research, we evaluate the effectiveness of two polymers of maleic acid, i.e., the homopolymer (pma) and the terpolymer (tpma), along with citric acid (ca) for crosslinking cotton cellulose., pma, tpma, and ca have molecular structures similar to btca, but are more cost effective. We have found that pma and tpma are less effective crosslinking agents for cotton than btca, probably due to the low mobility of the anhydride intermediate formed by pma or tpma to access the cellulosic hydroxyl during the curing process. We have found that the hydroxyl of ca and other α-hydroxylpolycarboxylic acids hinder the esterification of those acids with cellulose. The infrared spectroscopy data indicate that ca esterifies the anhydride intermediates of pma and tpma on cotton fabric under curing conditions. Consequently, ca is transformed from a trifunctional acid to a tetrafunctional one with the formation of an ester linkage with pma or tpma.

Infrared spectroscopy studies of the cyclic anhydride as the intermediate for the ester crosslinking of cotton cellulose by polycarboxylic acids. III. Molecular weight of a crosslinking agent

Polycarboxylic acids have been used as nonformaldehyde crosslinking agents for cotton fabrics to replace the traditional N-methylol reagents. In this research, we compared 1,2,3,4-butanetetracarboxylic acid (BTCA) with poly(maleic acid) (PMA) as crosslinking agents for cotton cellulose. BTCA and PMA have similar molecular structures with carboxyl groups bonded to their molecular backbones, and both form five-membered cyclic anhydride intermediates during a curing process. However, BTCA is a more effective crosslinking agent for cotton cellulose than PMA. This is mainly attributed to the differences in the mobility of the anhydride intermediates to access the cellulosic hydroxyl groups during a curing process. The mobility of the anhydride intermediate of PMA is reduced due to its molecular size and multiple bonding between a PMA molecule and cellulose. Consequently, more anhydride and less ester are detected on the cotton fabric treated with PMA than on the fabric treated with BTCA. The amount of the unreacted anhydride intermediate on the fabric treated with PMA is reduced whereas the amount of ester is increased when another hydroxyl-containing compound of low molecular weight is present. Thus, the infrared spectroscopy data show a clear link between the molecular weight of a polycarboxylic acid and its effectiveness for crosslinking cotton cellulose. © 1997 John Wiley & Sons, Inc.

Formation of Cyclic Anhydride Intermediates and Esterification of Cotton Cellulose by Multifunctional Carboxylic Acids: An Infrared Spectroscopy Study

Multifunctional polycarboxylic acids have been used as nonformaldehyde cross linking agents for cotton fabrics to replace the traditional N-methylol reagents. Ester ification of cotton cellulose by seventeen aliphatic and aromatic polycarboxylic acids is studied using Fourier transform infrared spectroscopy. Five-membered cyclic an hydride intermediates formed under the curing conditions are identified on cotton fabrics treated with these acids. Only those polycarboxylic acids that form cyclic an hydride intermediates esterify cotton cellulose. Formation of the cyclic anhydride intermediates and esterification of cotton cellulose take place in the same curing tem perature regions. The infrared spectroscopy data also indicate that the second carboxyl group in a bifunctional carboxylic acid is not able to esterify cotton cellulose effectively. Therefore, we can conclude that a polycarboxylic acid esterifies cotton cellulose through the formation of a cyclic anhydride intermediate. The infrared spectroscopy data also reveal that 1,2,3,4-butanetetracarboxylic acid is the most effective crosslinking agent for cotton cellulose among the acids studied.

Infrared spectroscopy studies of the cyclic anhydride as the intermediate for the ester crosslinking of cotton cellulose by polycarboxylic acids. II. Comparison of different polycarboxylic acids

Polycarboxylic acids have been used as crosslinking agents for cotton cellulose. In our previous research, we used Fourier transform infrared (FT-IR) spectroscopy to investigate the formation of five-membered cyclic anhydride intermediates on cotton fabric by different polycarboxylic acids. In this research, we found that those polycarboxylic acids capable of forming both five- and six-membered cyclic anhydrides form only five-membered cyclic anhydrides. We compared the effectiveness of the polycarboxylic acids with different molecular structures for esterifying cellulose. Those polycarboxylic acids, which have their carboxyl groups bonded to the adjacent carbons of their molecular backbones and are capable of forming five-membered cyclic anhydrides, are more effective for esterifying cellulose than those polycarboxylic acids having their carboxyl groups bonded to the alternative carbons. The only six-membered cyclic anhydride identified is the anhydride formed on the cotton fabric treated with poly(acrylic acid). © 1996 John Wiley & Sons, Inc.