Drug Screening Boosted by Hyperpolarized Long‐Lived States in NMR

Transverse and longitudinal relaxation times (T_1ρ and T₁) have been widely exploited in NMR to probe the binding of ligands and putative drugs to target proteins. We have shown recently that long‐lived states (LLS) can be more sensitive to ligand binding. LLS can be excited if the ligand comprises at least two coupled spins. Herein we broaden the scope of ligand screening by LLS to arbitrary ligands by covalent attachment of a functional group, which comprises a pair of coupled protons that are isolated from neighboring magnetic nuclei. The resulting functionalized ligands have longitudinal relaxation times T₁(¹H) that are sufficiently long to allow the powerful combination of LLS with dissolution dynamic nuclear polarization (D‐DNP). Hyperpolarized weak “spy ligands” can be displaced by high‐affinity competitors. Hyperpolarized LLS allow one to decrease both protein and ligand concentrations to micromolar levels and to significantly increase sample throughput.     

Investigation of microstructure of the acrylonitrile‐styrene‐glycidyl methacrylate terpolymers by 1D and 2D NMR spectroscopy

Acrylonitrile‐styrene‐glycidyl methacrylate (N/S/G) terpolymers were prepared by bulk polymerization by using benzoyl peroxide as initiator and analyzed by NMR spectroscopy. The compositions of terpolymers were determined by quantitative ¹³C{¹H}‐NMR spectra and compared with those calculated by Goldfinger's equation by using comonomer reactivity ratios: r_NS = 0.04, r_SN = 0.40; r_NG = 0.22, r_GN = 1.37; r_SG = 0.44, r_GS = 0.53. The ¹³C{¹H}‐ and ¹H‐NMR spectra were overlapping and complex. The spectral assignments were done with the help of distortionless enhancement by polarization transfer and two‐dimensional ¹³C‐¹H heteronuclear single quantum correlation experiments. 2D total correlated spectroscopy was used to ascertain the various coupling between the protons. The methyl, methine, methylene, and oxymethylene carbon resonances showed compositional sensitivity. 2D nuclear Overhauser enhancement spectroscopy (NOESY) experiment was used to ascertain the spatial proton–proton couplings. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1779–1790, 2003     

Miscibility and morphology of chiral semicrystalline poly‐(R)‐(3‐hydroxybutyrate)/chitosan and poly‐(R)‐(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate)/chitosan blends studied with DSC, 1H T1 and T1ρ CRAMPS

The phase structure of poly‐(R)‐(3‐hydroxybutyrate) (PHB)/chitosan and poly‐(R)‐(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (P(HB‐co‐HV))/chitosan blends were studied with ¹H CRAMPS (combined rotation and multiple pulse spectroscopy). ¹H T₁ was measured with a modified BR24 sequence that yielded an intensity decay to zero mode rather than the traditional inversion‐recovery mode. ¹H T_1ρ was measured with a 40‐kHz spin‐lock pulse inserted between the initial 90° pulse and the BR24 pulse train. The chemical shift scale is referenced to the methyl group of PHB as 1.27 ppm relative to tetramethylsilane (TMS) based on ¹H liquid NMR of PHB. Single exponential T₁ decay is observed for the β‐hydrogen of PHB or P(HB‐co‐HV) at 5.4 ppm and for the chitosan at 3.7 ppm. T₁ values of the blends are either faster than or intermediate to those of the plain polymers. The T_1ρ decay of β‐hydrogen is bi‐exponential. The slow T_1ρ decay component is interpreted as the crystalline phase of PHB or P(HB‐co‐HV). The degree of crystallinity decreases with increasing wt % of chitosan in the blend. The fast T_1ρ of β‐hydrogen and the T_1ρ of chitosan in the blends either follow the same trend as or faster than the weight‐averaged values based on the T_1ρ of the plain polymers. Together with the observation by differential scanning calorimeter (DSC) of a melting point depression and one effective glass transition temperature in the blends, the experimental evidence strongly suggests that chitosan is miscible with either PHB or P(HB‐co‐HV) at all compositions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1253–1258, 2002     

Characterization of morphology in chemically modified styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene by solid‐state nuclear magnetic resonance

Multiphase triblock styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene (SEBS) copolymers chemically modified with maleic anhydride (MAH) in the presence of a radical initiator by reactive extrusion were studied by solid‐state ¹H‐NMR and ¹³C‐NMR. In the experiments performed, the concentrations of MAH and initiator were kept constant, whereas the temperature profile in the extruder was varied. Samples with known extents of grafting and crosslinking were analyzed with NMR with techniques based on proton spin diffusion to investigate the microphase structure of the modified copolymers. The ¹³C‐NMR results show that the size of the rigid domains was about 15 nm and was not significantly changed by the modification. Alterations in the rubbery phase were illustrated by measured changes in proton spin‐spin (T₂) relaxation times. The fraction of protons having intermediate mobilities increased slightly in modified SEBS with respect to that observed in unmodified copolymers. These results were found to be independent of the extruder temperature profiles used, at least in the range studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Sequencing of N‐vinyl‐2‐pyrrolidone/glycidyl methacrylate copolymers by one‐dimensional and two‐dimensional nuclear magnetic resonance spectroscopy

Copolymers of N‐vinyl‐2‐pyrrolidone (V) and glycidyl methacrylate (G) monomers of different compositions were prepared by free‐radical solution polymerization. The copolymer composition of these copolymers was determined with ¹H‐NMR spectra. The reactivity ratios calculated from the Kelen–Tudos and nonlinear least‐square error‐in‐variable methods were r_V = 0.03 ± 0.01 and r_G = 5.05 ± 0.84 and r_V = 0.02 and r_G = 4.72, respectively. The triad sequence distribution in terms of V and G centered triads was determined from ¹³C{¹H}‐NMR spectroscopy. The complete spectral assignment of ¹³C{¹H}‐ and ¹H‐NMR spectra was performed with the help of distortionless enhancement by polarization transfer and two‐dimensional ¹³C–¹H heteronuclear single quantum coherence. The ¹H–¹H couplings were explained with total correlation spectroscopy and nuclear Overhauser enhancement spectroscopy spectra. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 50–60, 2002; DOI 10.1002/app.10186     

Microstructure analysis of N‐vinyl‐2‐pyrrolidone/vinyl acetate copolymers by NMR spectroscopy

N‐Vinyl‐2‐pyrrolidone (V) and vinyl acetate (A) copolymers of different compositions were synthesized by free radical bulk polymerization. The copolymer composition of these copolymers was determined using quantitative ¹³C{¹H} NMR spectra. The reactivity ratios for these comonomers were determined using the Kelen–Tudos (KT) and non‐linear least‐square error‐in‐variable (EVM) methods. The reactivity ratios calculated from the KT and EVM methods are r_V = 2.86 ± 0.16, r_A = 0.36 ± 0.09 and r_V = 2.56, r_A = 0.33, respectively. ¹H, ¹³C{¹H} and ¹H–¹³C heteronuclear shift correlation spectroscopy (HSQC) and ¹H–¹H homonuclear total correlation spectroscopy (TOCSY) were used for the compositional and configurational assignments of V/A copolymers. The ¹³C distortionless enhancement by polarization transfer (DEPT) technique was used to resolve the methine, methylene and methyl resonance signals in the V/A copolymers. © 2002 Society of Chemical Industry     

An investigation of 1H and 13C longitudinal relaxation and relaxation in the rotating frame in solid poly(N‐vinylcarbazole)

¹H and ¹³C longitudinal relaxation times (T₁) and relaxation times in the rotating frame (T_1ρ) have been measured for poly(N‐vinylcarbazole) in the solid state in air and nitrogen atmospheres in an attempt to elucidate molecular motions. In air, the T₁ relaxation of both ¹H and ¹³C was dominated by interaction with absorbed paramagnetic oxygen. In nitrogen, the ¹³C T₁ relaxation times were long (>300 s) and were averaged by ¹³C–¹³C spin diffusion. The ¹³C T_1ρ relaxation times showed an exponential dependence on the strength of the rotating ¹³C magnetic field and were thus controlled by spin–spin processes rather than spin–lattice processes. © 2001 Society of Chemical Industry     

The architecture of hydroxy‐functionalized aPS‐b‐random copolymer‐b‐PE via one‐pot strategy combining living free radical polymerization with coordination polymerization

The copolymerization of styrene with ethylene was promoted by CpTiCl₃/BDGE/Zn/MAO catalyst system combining free radical polymerization with coordination polymerization via sequential monomer addition strategy in one‐pot. The effect of polymerization conditions such as temperature, time, ethylene pressure, and Al/Ti molar ratio on the polymerization performance was investigated. The hydroxy‐functionalized aPS‐b‐random copolymer‐b‐PE triblock copolymer was obtained by solvent extraction and determined by GPC, DSC, WAXD, and ¹³C‐NMR. The DSC result indicated that the aPS‐b‐random copolymer‐b‐PE had a T_g at 87°C and a T_m at 119°C which attributed to the T_g of aPS segment and the T_m of PE segment, respectively. The microstructure of the hydroxy‐functionalized aPS‐b‐random copolymer‐b‐PE was further confirmed by WAXD, ¹³C‐NMR, and ¹H‐NMR analysis; and these results demonstrated that the obtained block copolymer consisted of aPS segment, S‐E random copolymer segment, and crystalline PE segment. The connection polymerization of the hydroxy‐functionalized aPS with random copolymer‐b‐PE was revealed by GPC results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Limits to expanding the PN‐F series of polyphosphazene elastomers

Mixed‐substituent fluoroalkoxyphosphazene polymers bearing ～15% 1H,1H,2H,2H‐perfluorooctan‐1‐oxy or 1H,1H,2H,2H‐perfluorodecan‐1‐oxy side groups together with trifluoroethoxy cosubstituent groups were synthesized. The low reactivity of the long‐chain fluoroalkoxides and their limited solubility in organic solvents prevented higher levels of substitution. Moreover, the sodium alkoxides with two methylene residues adjacent to the oxygen proved to be unstable in solution due to elimination of NaF and precipitation of side products, and this limited the time available for chlorine replacement reactions. The resulting cosubstituent polymers were characterized by proton nuclear magnetic resonance (¹H‐NMR), ³¹P‐NMR, ¹⁹F‐NMR, gel‐permeation chromatography, and differential scanning calorimetry. Unlike homo‐ or mixed‐substituent fluoroalkoxyphosphazene polymers, such as [NP(OCH₂CF₃)₂]_n (a microcrystalline thermoplastic, T_g ～ ?63°C, T_m ～ 242°C) or [NP(OCH₂CF₃)(OCH₂(CF₂)_xCF₂H)]_n (PN‐F, a rubbery elastomer, T_g ～ ?60°C, but no detectable T_m), the new polymers are gums (T_g ～ ?50°C, but no detectable T_m) with molecular weights in the 10⁵ g/mol rather than the 10⁶ g/mol range. POLYM. ENG. SCI., 54:1827–1832, 2014. © 2013 Society of Plastics Engineers     

Structural changes of bulk polyethylene by stress impact as studied by solid‐state NMR

Solid‐state ¹³C‐ and ¹H‐NMR spectra of bulk high‐density polyethylene samples, cylindrical in form, to which stress impacts were applied with a home‐made stress‐impact apparatus, were measured. The fraction of the noncrystalline component increases with an increase in the stress‐impact strength. In the crystalline region, the monoclinic crystalline component appear with the stress impact, in addition to the major orthorhombic crystalline component. Furthermore, dynamic characterization was carried out on the basis of the observed values of the relaxation parameters ¹H T₂ and T_CH of the ¹H and ¹³C nuclei. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2268–2272, 2001     

Microstructure determination and thermal studies of n‐acryloylcarbazole/vinyl acetate copolymers

Copolymers of N‐acryloylcarbazole (A) and vinyl acetate (V) were synthesized by bulk polymerization using benzoyl peroxide (BPO) as free‐radical initiator at 65°C in different in‐feed ratios. The composition of the copolymer was determined by ¹H‐NMR spectrum. The comonomer reactivity ratios, determined by Kelen–Tudos (KT) and nonlinear error‐in‐variables (EVM) methods, were r_A= 16.75 ± 1.38, r_V = 0.015 ± 0.002, and r_A = 16.36, r_V = 0.015, respectively. Complete spectral assignments of the ¹H and ¹³C{¹H} NMR spectra of the copolymers were done by the help of distortionless enhancement by polarization transfer (DEPT) and two‐dimensional NMR techniques such as heteronuclear single quantum coherence (HSQC) and total correlation spectroscopy (TOCSY). The methine and methylene carbon resonances were found to be compositional as well as configurational sensitive. The signals obtained were broad pertaining to the restricted rotation of bulky carbazole group. The thermal stability and glass‐transition temperatures (T_g) of the copolymers were found to be dependant on polymer composition and characteristic of rotational rigidity of the polymer chain. Variation in the values of T_g with the copolymer composition was found to be in good agreement with theoretical values obtained from Johnston and Barton equations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2720–2733, 2007     

Structural investigations of (9‐ethyl‐carbazol‐6‐yl) methyl methacrylate/methyl acrylate copolymers using two‐dimensional NMR spectroscopy

(9‐Ethyl‐carbazol‐6‐yl) methyl methacrylate/methyl acrylate (E/A) copolymers of different compositions were prepared by solution polymerization by varying the molar infeed ratio, using AIBN as initiator at 60°C. The reactivity ratios calculated by Kelen–Tudos (KT) method were found to be r_E = 1.16 ± 0.02 and r_A = 0.69 ± 0.01 whereas those calculated from RREVM method were found to be r_E = 1.18 and r_A = 0.68. The molecular weights (M_w) and polydispersity index (PDI, M_w/M_n) were determined using gel permeation chromatography (GPC). Glass transition temperatures (T_g) for different compositions of E/A copolymers were determined using differential scanning calorimetry (DSC). Copolymer molar outfeed ratio (F_E) was calculated from ¹H NMR spectra. The α‐methyl, methine, backbone methylene, and quaternary carbon resonance signals of the copolymers were distinguished using ¹³C{¹H}, DEPT‐45, ‐90, and ‐135 NMR techniques. The α‐methyl and β‐methylene showed compositional and configurational sensitivity up to pentad and tetrad level, respectively, whereas methine showed only compositional sensitivity up to pentad level. Unambiguous assignments for ¹H and ¹³C{¹H} NMR spectra were done by correlating 1D (¹H, ¹³C{¹H}, DEPT) and 2D (HSQC, TOCSY) NMR data. The spectral assignments for carbonyl region were done by studying higher bond order couplings by heteronuclear multibond correlation (HMBC) spectra. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5595–5606, 2006     

Synthesis and characterization of a random terpolymer of L‐lactide, ϵ‐caprolactone and glycolide

A random terpolymer of L ‐lactide (LL), ?‐caprolactone (CL) and glycolide (G) has been synthesized in bulk at 130 °C using stannous octoate as the coordination–insertion initiator. The terpolymer, poly(LL‐ran‐CL‐ran‐G), has been characterized by a combination of analytical techniques: GPC, ¹H NMR, ¹³C NMR, DSC and TG. Molecular weight characterization by GPC shows a unimodal molecular weight distribution with values of M _n = 1.01 × 10⁵ g mol^?1 and M _w / M _n = 2.17. Compositional and microstructural analysis by ¹H NMR and ¹³C NMR, respectively, reveal a terpolymer composition of LL:CL:G = 74:15:11 (mol%) with a chain microstructure consistent with random monomer sequencing. This latter view is supported by the terpolymer temperature transitions (T_g and T_m) from DSC and the thermal decomposition profile from TG. The results and, in particular, the conclusion that it is a random rather than a statistical terpolymer are discussed in the light of current theories regarding the mechanism of this type of polymerization. © 2001 Society of Chemical Industry     

Condition monitoring of a thermally aged hydroxy‐terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) elastomer by nuclear magnetic resonance cross‐polarization recovery times

A hydroxy‐terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) elastomer is commonly used as propellant binder material. The thermal degradation of the binder is believed to be an important parameter governing the performance of the propellant. The aging of these binders can be monitored by mechanical property measurements, such as modulus or tensile elongation. These techniques, however, are not easily adapted to binder agents that are dispersed throughout a propellant. In this paper we investigated solid‐state nuclear magnetic resonance (NMR) relaxation times as a means to predict the mechanical properties of the binder as a function of aging time. Proton (¹H) spin–lattice and spin–spin relaxation times were insensitive to the degree of thermal degradation of the elastomer. Apparently, these relaxation times depend on localized motions that are only weakly correlated with mechanical properties. A strong correlation was found between the ¹³C cross‐polarization (CP) NMR time constant, T_cp, and the tensile elongation at break of the elastomer as a function of aging time. A ramped‐amplitude CP experiment was less sensitive to imperfections in setting critical instrumental parameters for this mobile material. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 453–459, 2001     

Thermotropic main‐chain liquid‐crystalline photodimerizable poly(vanillylidenealkyloxy alkylphosphate ester)s containing a cyclopentanone moiety

A new class of main‐chain liquid‐crystalline photodimerizable vanillylidene‐containing alkylpolyphosphate esters were synthesized from 2,5‐bis[m‐hydroxyalkyloxy(vanillylidene)] cyclopentanones with various alkylphosphoro‐ dichloridates by solution polycondensation in chloroform at ambient temperature. Their chemical structures were confirmed by FT‐IR, ¹H, ¹³C and ³¹P NMR spectroscopic analysis. Dilute‐solution viscosity values were measured in order to obtain the intrinsic viscosities of the synthesized polymers. Mesogenic properties and phase behavior were investigated by the use of hot‐stage optical polarized microscopy and differential scanning calorimetry. Thermogravimetric analysis revealed that all of the polymers were stable up to 170–230 °C and decomposed with high char yields. The shorter methylene‐chain‐containing polymers did not show a liquid‐crystalline phase, while the longer methylene‐chain‐ containing polymers showed grainy and nematic textures. The T_g, T_m and T_i values of the polymers decreased with increasing flexible methylene chain length in the polymer backbones. The photocrosslinking properties of the polymers were studied by UV light/UV spectroscopy; the crosslinking proceeds via 2π–2π cycloaddition reactions of the vanillylidene exocyclic double bonds of the polymers. The rate of crosslinking was faster for the pendant ethoxy‐containing polymers than that of the pendant methoxy‐containing polymers. Copyright © 2005 Society of Chemical Industry     

Novel and Mild Route to Phthalocyanines and 3‐Iminoisoindolin‐1‐ones via N,N‐Diethylhydroxylamine‐Promoted Conversion of Phthalonitriles and a Dramatic Solvent‐Dependence of the Reaction

Refluxing a mixture of phthalonitrile C₆R¹R²R³R⁴(CN)₂ 1 (R¹–R⁴=H), or its substituted derivatives 2 (R¹, R³, R⁴=H, R²=Me), or 3 (R¹, R⁴=H, R², R³=Cl) (1 equiv.) and N,N‐diethylhydroxylamine, Et₂NOH, (4 equivs.) in methanol for 4 h results ( Route A ) in precipitation of the symmetrical ( 6 and 8 ) and an isomeric mixture of unsymmetrical ( 7 ) phthalocyanines, isolated in good (55–65 %) yields. The reaction of phthalonitriles 1 , 2 , or 4 (R¹, R³, R⁴=H, R²=NO₂) (4 equivs.) with Et₂NOH (8 equivs.) in the presence of a metal salt MCl₂ (M=Zn, Cd, Co, Ni) (1 equiv.) in n‐BuOH or without solvent results in the formation of metallated phthalocyanine species ( 9 – 17 ). Upon refluxing in freshly distilled dry chloroform, phthalonitrile 1 or its substituted analogues 2 , 3 or 5 (R¹–R⁴=F) (1 equiv.) react with N,N‐diethylhydroxylamine (2 equivs.) affording 3‐iminoisoindolin‐1‐ones 18 – 21 ( Route B ) isolated in good yields (55–80 %). All the prepared compounds were characterized with C, H, and N elemental analyses, ESI‐MS, IR, and compounds 18 – 21 also by 1D (¹H, ¹³C{¹H}), and 2D (¹H,¹⁵N‐HMBC and ¹H,¹³C‐HMQC, ¹H,¹³C‐HMBC) NMR spectroscopy.     

Binary copolymerization of 4‐methyl‐1,3‐pentadiene with styrene,butadiene and isoprene catalysed by a titanium [OSSO]‐type catalyst

Binary copolymerization of 4‐methyl‐1,3‐pentadiene (4MPD) with styrene, butadiene and isoprene promoted by the titanium complex dichloro{1,4‐dithiabutanediyl‐2,2′‐bis[4,6‐bis(2‐phenyl‐2‐propyl)phenoxy]}titanium activated by methylaluminoxane is reported. All the copolymers are obtained in a wide range of composition and the molecular weight distributions obtained from gel permeation chromatographic analysis of the copolymers are coherent with the materials being copolymeric in nature. The copolymer microstructure was fully elucidated by means of ¹H NMR and ¹³C NMR spectroscopy. Differential scanning calorimetry shows an increase of glass transition temperature (T_g) with the amount of 4MPD in the copolymers with butadiene and isoprene, while in the copolymers with styrene T_g is increased on increasing the amount of styrene. © 2016 Society of Chemical Industry     

Palladium‐Catalysed Intramolecular Direct Arylation of 2‐Bromobenzenesulfonic Acid Derivatives

A palladium‐catalysed intramolecular direct arylation of 2‐bromobenzenesulfonic acid derivatives was found to proceed using 1 mol% of palladium acetate as the catalyst. The influence of the substituents on the phenol moiety of 2‐bromobenzenesulfonic acid phenyl esters reveals that electron‐donating substituents favour the reaction while electron‐withdrawing ones are unfavourable. The reactivity of sulfonamides was also studied and, in all cases, a selective activation at sp² C H vs. sp³ C H was observed. A sulfonamide bearing both phenyl and benzyl substituents on nitrogen gave selectively the six‐membered ring product.     

Synthesis and characterization of poly(ethylene oxide)‐based glycopolymers and their biocompatibility with osteoblast cells

Poly(ethylene oxide)‐block‐poly(methacryl‐d ‐glucopyranoside) (PEO‐GP) and poly(methacryl‐d ‐glucopyranoside) (H‐GP) glycopolymers were synthesized by deacetylation of acetylated polymers which were synthesized via atom transfer radical polymerization. The synthesized glycopolymers were characterized using ¹H NMR, ¹³C NMR and Fourier transform infrared (FTIR) spectroscopies, gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The deacetylated polymers exhibited onset decomposition temperatures about 60 °C lower compared to the polymers having acetyl pendants. The glass transition temperature (T_g) of the acetylated homopolymer was 133 °C and that of the PEO‐based block copolymer was 124 °C. The deacetylated polymers H‐GP and PEO‐GP exhibited T_g values of about ?30 °C. Biocompatibility of the H‐GP and PEO‐GP glycopolymers was obtained by studying osteoblast cell adhesion, viability and proliferation in vitro. The cell viability showed an increase with increasing concentration of H‐GP from 0.1 to 1 µmol L^?1 and then decreased with further increase in its concentration (10–1000 µmol L^?1). PEO‐GP did not show a significant variation in cell viability on variation of its concentration from 0.1 to 1000 µmol L^?1. The significant improvement in biocompatibility with osteoblast cells in the presence of PEO‐GP was considered as due to the covalently bonded PEO segment of the methacrylate glycopolymer block. © 2014 Society of Chemical Industry     

Characterization of poly(1‐methyl‐1,4‐butanediol‐1,4‐diyl/2,3,4‐trihydro‐5‐methylfuran‐2,5‐diyl) prepared from natural rubber through 2D NMR spectroscopy

Poly(1‐methyl‐1,4‐butanediol‐1,4‐diyl/2,3,4‐trihydro‐5‐methylfuran‐2,5‐diyl) was prepared by epoxidation of deproteinized natural rubber with m‐chloroperbenzoic acid followed by hydrolysis with sulfuric acid. Characterization of the resulting product was performed through FT‐IR, ¹H NMR, and ¹³C NMR spectroscopies. All signals appearing in the ¹H and ¹³C NMR spectra were assigned by distortionless enhancement by polarization transfer (DEPT), quaternary carbon observation (QUAT), correlation spectroscopy (COSY), and heteronuclear multiple quantum correlation (HMQC) measurements. After proving the primary structure of the product, one pot synthesis of poly(1‐methyl‐1,4‐butanediol‐1,4‐diyl/2,3,4‐trihydro‐5‐methylfuran‐2,5‐diyl) from deproteinized natural rubber latex was carried out with peracetic acid and 2‐propanol. The resulting product was characterized by ¹H NMR spectroscopy on the basis of the assignments established in this study, and its gas permeability was measured for a practical application as a film. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.