Synthesis of methyldiethylsilylmethyl vinyl ether

Conclusions Methyldiethylsilylmethyl vinyl ether was synthesized by the reaction of the corresponding alcohol with acetaldehyde and hydrogen chloride, followed by the subsequent dehydrochlorination of the formed organosilicon -chloro ether.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1085–1086, May, 1971.     

Concise syntheses of bacteriohopanetetrol and its glucosamine derivative

This study describes the syntheses of bacteriohopanetetrol and its glucosamine derivative through a key direct coupling of a ribose derivative to the hopane skeleton.     

Synthesis and characterization of deuterated poly(arylene ether sulfones)

Selectively deuterated poly(arylene ether sulfones) were prepared for neutron scattering studies and for deuterium NMR investigations. The availability of these model macromolecules permits molecular-level identification of the motions responsible for the low temperature relaxations that have been observed in the dynamic mechanical spectra of these engineering polymers. Three labeled sites on the appropriate monomers (bisphenol-A and 4,4′-dichlorodiphenylsulfone) were prepared from deuterated intermediates and characterized via chromatographic, spectroscopic, and thermal analysis. The deuterium exhcange between methyl and aromatic sites that occurred during synthesis was quantified. These labeled monomers were mixed with hydrogenous monomers to synthesize high molecular weight, selectively deuterated poly(arylene ether sulfones). A synthetic technique involving N-methyl-2-pyrrolidone/potassium carbonate was employed to afford high molecular weight polymers. The polymers were characterized by FT-IR, proton, carbon, and deuterium NMR, intrinsic viscosities, and thermal analysis. Molecular weights of the labeled polymers were similar to unlabeled systems.     

Synthesis of deuterated derivative of β-D-glucopyranosyl 1-cetyl phosphate

Conclusions The deuterated derivative of -D-glucopyranosyl 1-cetyl phosphate was synthesized by opening the 1,2-alkyl orthoacetate of D-glucose.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2628–2629, November, 1979.     

Synthesis of N-aminoglycoside from the monoethanolamine vinyl ether

Russian Journal of General Chemistry -     

Spectroscopic studies of poly(vinyl chloride) and its deuterated derivatives

Poly(vinyl chloride) (PVC) and all its deuterated derivatives were prepared by variation of the polymerization method and polymerization temperature to study the structure of PVC and the mechanism of addition polymerization by infrared spectroscopy and high resolution NMR spectroscopy. The CH and CH₂ stretching modes of PVC were assigned completely from the infrared spectra of PVC-αd₁, PVC-β,βd₂ and PVC-d₃. The frequencies of the CCI stretching modes of the polymers depended not only on the substituents in the trans position to the Cl atom across both adjacent C? C bonds, but also on the atom attached to the C atom of the C? Cl bond. The frequency shifts were used to assign the CCl stretching modes of PVC-βd₁ and PVC-α,βd₂ and to study the opening of the double bond of VC in the addition polymerization. The differences of the chemical shifts of the α and β protons of PVC due to the tacticity were determined experimentally by PVC-β,βd₂ and PVC-αd₁ without using the spin-decoupling technique. With PVC-α,βd₂, the conception of the tetrad was required to interpret the four observed peaks whose intensities changed with the polymerization temperature and the trans–cis composition of the monomer used.     

Theoretical modeling of infrared spectra of benzoic acid and its deuterated derivative

Theoretical simulation of the ν_s stretching band is presented for benzoic acid and its OD derivative at 300 K. The simulation takes into account an adiabatic coupling between the high-frequency O–H(D) stretching and the low-frequency intermolecular OO stretching modes, linear and quadratic distortions of the potential energy for the low-frequency vibrations in the excited state of the O–H(D) stretching vibration, resonance interaction between the two hydrogen bonds in the dimer, and Fermi resonance between the fundamental ν OH(D) stretching and the overtone of the δ O–H(D) bending vibrations.

Infrared, far-infarared, Raman and low-frequency Raman spectra of the polycrystalline benzoic acid and its deuterated form have been measured. The geometry and experimental frequencies are compared with the results of our B3LYP/6-311++G** and B3LYP/cc-pVTZ calculations.     

Synthesis and characterization of amphiphilic diblock copolymers of methyl tri(ethylene glycol) vinyl ether and isobutyl vinyl ether

Water-soluble diblock copolymers of methyl tri(ethylene glycol) vinyl ether (hydrophilic block) and isobutyl vinyl ether (hydrophobic block) of different molecular weights and composition were synthesized by living cationic polymerization. The molecular weight and comonomer composition of these copolymers were determined by GPC and ¹H NMR spectroscopy, respectively. Aqueous solutions of the copolymers were characterized in terms of their micellar behavior using dynamic light scattering, aqueous GPC, and dye solubilization. All the copolymers formed aggregates with the exception of a diblock copolymer with only two hydrophobic monomer units. The micellar hydrodynamic size scaled with the 0.61 power of the number of hydrophobic units, in good agreement with a theoretical exponent of 0.73. An increase in the length of the hydrophobic block at constant hydrophilic block length or an increase in the overall polymer size at constant block length ratio both resulted in lower critical micelle concentrations (cmcs). The cloud points of 1% w/w aqueous solutions of the polymers were determined by turbidimetry. An increase in the length of the hydrophobic block at constant hydrophilic block length caused a decrease in the cloud points of the copolymers. However, an increase in the overall polymer size at constant block length ratio led to an increase in the cloud point. © 1996 John Wiley & Sons, Inc.     

Synthesis of new vinyl ether functionalized silica for UV-patterning

We report a new ORganically MOdified SILicates (ORMOSILs) stable sol based on vinyl ether function which can be deposited as a layer and structured by mean of UV radiation through a mask or by direct laser writing. Silica matrix is synthesized by sol–gel process and organic network is formed by photopolymerization. One of the potential applications is the fabrication of integrated optical circuits. [2-(3,4 epoxycyclohexyl ethyltrimethoxysilane)] has already used for the fabrication of such devices and to develop microstructures on an organic substrate by cationic polymerization. Obtained results show some weakness such as an important contribution of OH and aliphatic CH groups to the attenuation at 1550 nm wavelength and low conversion rate of organic polymerization involving poor mechanical properties. This work treats on the design of a new generation of hybrid materials with a very high reactivity and low amount of groups involved in the attenuation. We have chosen vinyl ether function as reactive organic part for her highest polymerization rate via cationic way. The new synthesized molecule is 4-vinylether phenyltriethoxysilane. Sol–gel kinetic reactions were monitored by liquid ²⁹Si-NMR spectroscopy. In order to obtain the highest reactive multifunctional oligomers and the lowest OH groups, hydrolysis and polycondensation reactions were followed as a function of time, temperature and pH of the water involved in the hydrolysis conditions. Finally, we show the feasibility to microstructure films deposited with this sol.     

Synthesis of a poly(vinyl ether) containing a benzocyclobutene moiety and its reaction with dienophiles

1‐Benzocyclobutenyl vinyl ether (1) was easily prepared by the elimination reaction of hydrogen bromide from 1‐benzocyclobutenyl 1‐bromoethyl ether obtained by 1‐bromobenzocyclobutene and ethylene glycol via two steps in a good yield. Cationic polymerizations of 1 was carried out at −78°C for 2 h in toluene in the presence of BF₃OEt₂ as an initiator to give quantitatively the corresponding polymers (2) as white solids. As a model reaction of the polymer reaction of 2 with dienophiles, the Diels–Alder reactions of 1‐methoxybenzocyclobutene with maleic anhydride (MA) in toluene at 100–140°C for 3 h were carried out to obtain the corresponding Diels–Alder adduct quantitatively at 140°C. The polymer reactions of 2 with MA and N‐phenylmaleimide (MI) in toluene were carried out to yield the corresponding Diels–Alder adduct polymers in good yields. The degree of introduction of the dienophile could be controlled by temperature, and the unreacted benzocyclobutene moiety could further react with another benzocyclobutene moiety or dienophile. The properties (solubilities, T_g, and temperature of 10% weight loss) of the polymers obtained from the polymer reaction were quite different from those of 2. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 59–67, 1999     

Synthesis of isoacronycine and its pyranone analog

The Pechmann condensation of malic acid with 1,3-dihydroxy-10-methyl-9-acridanone ( 6 ), performed during the search for a synthetic approach to 5-methoxy-2,2,11-trimethyl-2H-pyrano[2,3-b]acridan-6-one (isoacronycine, 11a ), afforded 5-hydroxy-11-methyl-2H-pyrano[2,3-b)acridan-2,6-dione ( 7 ). This is the first example of a new heterocyclic ring system in which an acridanone and a pyranone ring have been fused. Compound 7 served as the intermediate for the preparation of 11a and was readily converted into the pyranone analog 9 of isoacronycine by known procedures. Spectral and chemical evidence distinguishing 11a from acronycine ( 12a ) is presented.     

Synthesis of silicon-containing vinyl ether monomers and oligomers and their photoinitiated polymerization

Silicon-containing divinyl ether monomers were synthesized by the addition reaction of glycidyl vinyl ether ( 1 ) with various silyl dichlorides using tetra-n-butylammonium bromide (TBAB) as a catalyst. The reaction of 1 with diphenyl dichlorosilane gave bis-[1-(chloromethyl)-2-(vinyloxy)-ethyl]diphenyl silane ( 3a ) in 89% yield. Polycondensations of 3a with terephthalic acid were also carried out using 1,8-Diazabicyclo[5.4.0]-7-undecene (DBU) to afford silicon-containing polyfunctional vinyl ether oligomers ( 5 ). A multifunctional Si-monomer with both vinyl ether and methacrylate groups ( 7 ) was prepared by the reaction of 3a with potassium methacrylate using TBAB as a phase transfer catalyst. Photoinitiated cationic polymerizations of these vinyl ether compounds proceeded rapidly using the sulfonium salt, bis-[4-(diphenyl-sulfonio)phenyl]sulfide-bis-hexafluorophoshate (DPSP), as the cationic photoinitiator in neat mixtures upon UV irradiation. Multifunctional monomer 7 with both vinyl ether and methacrylate groups showed “hybrid curing properties” using both DPSP and the radical photoinitiator, 2,4,6-trimethylbenzoyl diphenylphoshine oxide (TPO). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3217–3225, 1997     

Synthesis,UV-curing behavior and surface properties of fluorine-containing vinyl ether polymers

Five fluorine-containing vinyl ether monomers were prepared by the reaction between 2-vinyloxy ethanol, a fluorinated alcohol and hexafluorobenzene in the presence of sodium hydride in dimethylformamide. Two representative properties of these monomers, UV-curing behavior initiated by a cationic photo-initiator PAG 201 and surface free energy of coating films, were investigated. Photo-polymerization proceeded both rapidly and completely with a high double-bond conversion （〉 90%） and a fast curing rate （maximum curing time 〈 21 s） for three monomers. The surface energies of the monomers and the resulting polymer films were then investigated. The minimum surface free energy of the UV-cured homopolymer films reaches 7.1 mJ/m2. X-ray photoelectron spectroscopy data show that the low surthce tension is influenced by fluorine content in the soft segments and fluorinated chains＇ migration to the surface. The five monomers exhibit low viscosity, low surface energy, good thermal stability and good photo-polymerization properties, which make them great candidates for UV coating and photoresist applications.     

Synthesis of the deuterated thymidine-d9 and deuterated oligonucleotides

The efficient synthesis of the highly-deuterated thymidine-d₉ by the glycosylation reaction between a deuterated nucleobase and deuterated sugar is described. It is also incorporated into the oligonucleotides using a DNA synthesizer. Using this approach, it is possible to make highly-deuterated oligonucleotides for biological studies and structural analyses.     

Mechanistic and kinetic study on the ozonolysis of ethyl vinyl ether and propyl vinyl ether

The reaction mechanisms for ozonolysis of ethyl vinyl ether (EVE) and propyl vinyl ether (PVE) have been investigated using the density functional theory (DFT) and ab initio method. Cycloaddition reactions of O₃ to EVE and PVE are highly exothermic by 52.91 and 53.17 kcal/mol, respectively. Major products (formaldehyde, ethyl formate, and propyl formate) resulting from the both reactions are identified by comparing them with the experimental results. Further reactions of the most energy-rich Criegee intermediates (C₂H₅OCHOO and C₃H₇OCHOO) have been proposed in the presence of NO and H₂O in which the main products are ethyl formate and propyl formate. The Multichannel Rice–Ramsperger–Kassel–Marcus (RRKM) approach is employed to calculate the total and individual rate constants for major product channels over a wide range of temperatures and different pressures. In the temperature range of 200–2500 K, the main path is the production of ethyl formate with k _EVE+O3 = 4.67 × 10⁻¹² exp(−3029/T), for the EVE with O₃ reaction and k _PVE+O3 = 3.58 × 10⁻¹² exp(−2858/T) for the PVE with O₃ reaction. At 298 K and 760 torr, the rate constants calculated are 1.80 × 10⁻¹⁶ and 2.45 × 10⁻¹⁶ cm³ molecule⁻¹ s⁻¹ for ozonolysis of EVE and PVE, which are consistent with the experimental results. The total rate constants show positive temperature dependence over the temperature range of 200–2000 K but pressure independence in the range of 0.01–10000 Torr. Estimation of branching ratios of several products is also performed. The influence of carbon chain length on reactivity toward ozone is examined.