A method of treating hepatitis virus infection is disclosed. The method comprising administering to a human subject in need of such treatment an effective hepatitis virus-combatting amount of an alkyl lipid or alkyl lipid derivative.

Metallocene compounds having two fluorenyl ligands bridged with a single silicon or germanium atom, said atom having two substituent groups containing a total of at least four carbon atoms, are useful as catalyst components for the polymerization of olefins. Particularly, it is possible to prepare high molecular weight atactic polypropylene with improved yields with respect to the known catalysts.

Disclosed is a process for preparing bridged Group 4 metal complexes containing a neutral diene ligand starting from the corresponding novel, metal diene containing complexes by reaction thereof with the divalent derivative of a bridged bidentate ligand compound. The novel, intermediate metal diene complexes, their formation from tetravalent metal salts and an integrated process combining both process steps are claimed.

Metal complexes useful as components of addition polymerization catalysts are prepared by oxidizing Group 4 or Lanthanide metal containing complexes using an organic halide oxidizing agent in a unique one electron oxidation.

A metallocene compound is provided wherein to a transition metal compound is bonded a multidentate compound wherein a substituted cycloalkadienyl ring CA1 having therein a heteroaromatic group Ra containing an oxygen, sulfur or nitrogen atom on a cycloalkadienyl ring, preferably the five-membered ring thereof, and an unsubstituted or substituted cycloalkadienyl group CA2 or --(R1)N--, --O--, --S-- or --(R1)P--, preferably CA2, more preferably a substituted cycloalkadienyl group identical with CA1 are bonded through a divalent linking group. The metallocene compound is suitable as a principal ingredient of a catalyst for the polymerization of olefins, particularly achieving a very high effect in making the molecular weight of a polypropylene higher.

The present invention relates to a process for preparing a methylene-bridged biscyclopentadienyl compound having the formula I ##STR1##where L are, independently of one another, identical or different and are each a cyclopentadienyl group, by reacting one or two cyclopentadienyl compounds LH with formaldehyde in monomeric, oligomeric or polymeric form or formaldehyde-generating reagents in the presence of at least one base and at least one phase transfer catalyst.

The invention provides an improved process for the synthesis of compounds carrying at least one phosphate group, especially polyalkylene glycol phosphate compounds, said process comprising the steps of: (a) reacting a compound containing at least one primary alcohol moiety with a diaryl- or diaralkyl-halophosphate whereby to form the corresponding diaryl- or diaralkyl-phosphate ester; (b) reductively cleaving the resulting product; and (c) if desired, repeating steps (a) and (b) with the product of step (b) whereby to produce a compound carrying two or more phosphate groups. Advantages of the process in accordance with the invention are that this avoids the production of by-products and results in products which are low in impurities. Also provided are novel diaryl- and diaralkyl-phosphate ester compounds, in particular polyethylene glycol diphenylphosphate ester and derivatives thereof.

A process to prepare an improved fluid rare earth phosphate catalyst composition useful in preparing alkylene oxide adducts of organic compounds having active hydrogen atoms is provided. The catalyst is prepared by dissolving a rare earth salt in a C9-C30 active hydrogen containing organic compound and then adding phosphoric acid to the organic compound rare earth mixture.

The invention relates to a process for preparing triethyl phosphate by reacting phosphorus oxychloride with a greater than stoichiometric quantity of ethanol under reduced pressure at temperatures of from 0 to 50° C. in a reaction vessel, wherein a) the volatile components resulting from the reaction are predominantly condensed by means of a reflux condenser and the remaining volatile components are passed into a scrubber filled with water,b) after the end of the reaction, the reaction mixture is separated distillatively in an outgassing column into a top product and a bottom product which predominantly comprises triethyl phosphate,c) the top product of the outgassing column is combined with the contents of the scrubber andd) the contents of the scrubber are separated distillatively in an azeotropic distillation to obtain water and ethanol as top product and the ethanol, preferably after dewatering, is preferably returned to the reaction.

A process for obtaining silicon-bridged metallocene compounds comprising the following steps: a) reacting, at a temperature of between −10° C. and 70° C., the starting ligand with about 2 molar equivalents of an alkylating agent;b) after the reaction has been completed, adding at least 2 molar equivalents of an alkylating agent that can be also different from the first one; andc) reacting, at a temperature of between −10° C. and 70° C., the product obtained from step b) with at least 1 molar equivalent of a compound of formula ML's, wherein M is a transition metal; s is an integer corresponding to the oxidation state of the metal; and L' is an halogen atom selected from chlorine, bromine and iodine.

A glass for a magnetic recording medium substrate permitting the realization of a magnetic recording medium substrate affording good chemical durability and having an extremely flat surface, a magnetic recording medium substrate comprised of this glass, a magnetic recording medium equipped with this substrate, and methods of manufacturing the same. The glass is an oxide glass not including As or F.

A separation membrane according to the present invention is characterized by having a porous tube containing an alumina as a main component and an attachment member disposed in a connection position of the porous tube, wherein the porous tube and the attachment member are bonded by a ceramic oxide-based bonding agent containing 17 to 48 wt % of SiO2, 2 to 8 wt % of Al2O3, 24 to 60 wt % of BaO, and 0.5 to 5 wt % of ZnO as essential components and containing at least one of La2O3, CaO, and SrO, and a thin zeolite layer is formed on a surface of the porous tube. The attachment member is bonded to the porous tube before the formation of the zeolite layer. Therefore, the bonding agent can have a melting temperature higher than 600° C., which is the upper heatproof temperature limit of the zeolite. Thus, the ceramic oxide material for the bonding agent can be selected from a wider range of compositions such as glass compositions (without limitations on the glass softening temperature).

There are provided a dielectric composition and a preparation method thereof, the dielectric composition including: a first perovskite powder for a core represented by ABO3: and a second perovskite powder for a shell represented by ABO3, having an average particle diameter corresponding to ⅓ to 1/10 of an average particle diameter of the first perovskite powder, and included in an amount of 1 to 70 parts by weight with respect to 100 parts by weight of the first perovskite powder, wherein particles of the second perovskite powder have pores having a volume fraction of 3 to 50 vol % therein. According to the present invention, there are provided a dielectric composition having excellent dielectric characteristics and electrical characteristics, and a preparation method thereof.

A process to separate a multi-component hydrocarbon stream which includes ethylene and other components with at least some of the components being present in a number of phases, is provided. The process includes in a first flash stage, flashing the multi-component hydrocarbon stream, from an elevated pressure and temperature to a pressure in the range of 10-18 bar(a), producing a first ethylene-containing vapor stream at a pressure in the range of 10-18 bar(a) and a multi-phase stream which includes some ethylene. In a second flash stage, the multi-phase stream is flashed to a pressure of less than 6 bar(a), producing a second vapor stream at a pressure of less than 6 bar(a) and a bottoms stream. The first ethylene-containing vapor stream is removed from the first flash stage, the second vapor stream is removed from the second flash stage and the bottoms stream is removed from the second flash stage.

A method for preparing fuel components from crude tall oil. Feedstock containing tall oil including unsaturated fatty acids is introduced to a catalytic hydrodeoxygenation to convert unsaturated fatty acids, rosin acids and sterols to fuel components. Crude tall oil is purified in a purification by washing the crude tall oil with washing liquid and separating the purified crude tall oil from the washing liquid. The purified crude tall oil is introduced directly to the catalytic hydrodeoxygenation as a purified crude tall oil feedstock. An additional feedstock may be supplied to the catalytic hydrodeoxygenation.

A catalyst comprising an aluminosilicate zeolite having an MOR framework type, an acidic MFI molecular sieve component having a Si/Al2 molar ratio of less than 80, a metal component comprising one or more elements selected from groups VIB, VIIB, VIII, and IVA, an inorganic oxide binder, and a fluoride component.

Provided are a negative active material, a method of preparing the same, and a lithium battery including the negative active material. The negative active material includes a carbonaceous core that has a sulfur content of about 10 ppm to 900 ppm; and an amorphous carbon layer continuously formed on a surface of the carbonaceous core, wherein the carbonaceous core has a crystalloid plate structure, and a crystallite size measured from a full width at half maximum of the peak with respect to the surface (002) of about 10 nm to about 45 nm in an X-ray diffraction spectrum of the carbonaceous core. The lithium battery including a negative electrode including the negative active material has improved capacity characteristics and ring lifetime characteristics.

The disclosure relates generally to a method for fabricating a patterned medium. The method includes providing a substrate with an exterior layer under a lithographically patterned surface layer, the lithographically patterned surface layer comprising a first pattern in a first region and a second pattern in a second region, applying a first masking material over the first region, transferring the second pattern into the exterior layer in the second region, forming self-assembled block copolymer structures over the lithographically patterned surface layer, the self-assembled block copolymer structures aligning with the first pattern in the first region, applying a second masking material over the second region, transferring the polymer block pattern into the exterior layer in the first region, and etching the substrate according to the second pattern transferred to the exterior layer in the second region and the polymer block pattern transferred to the exterior layer in the first region.

Methods for the synthesis of metal quantum clusters within the framework of a porous gel matrix are described. For example, Ag25(glutathione)18 quantum clusters are synthesized in a cross-linked polyacrylamide gel matrix. The methods can be performed on large-scale and yields monodispersed metal quantum clusters.

Set of compositions for preparing system-in-package type semiconductor device. The composition set consists of underfill composition for preparing underfill part and encapsulation resin composition for preparing resin encapsulation part. 1) A cured product of the underfill composition has a glass transition temperature, Tg, ≧100° C. and is the same with or differs from a Tg of a cured product of the encapsulation resin composition by ≦20° C. 2) Total linear expansion coefficient of the cured product of the underfill composition at a temperature not higher than (Tg−30)° C. and a linear expansion coefficient of the cured product of the encapsulation resin composition at a temperature not higher than (Tg−30)° C. is ≦42 ppm/° C. 3) A ratio of the linear expansion coefficient of the cured product of the encapsulation resin composition to the linear expansion coefficient of the cured product of the underfill composition ranges from 0.3 to 1.0.

An artificial silica marble comprises a matrix and a line pattern portion. The line pattern portion comprises fine lines having a width of about 50 to about 500 μm and forms a web- or net-like pattern. The line pattern portion divides or partitions the artificial silica marble into a plurality of irregularly shaped pattern portions to form an amorphous pattern in the cross section of the artificial silica marble.

The disclosure provides an ink jet ink for color filter and a method for preparing the same, as well as a method for preparing of a color filter. The ink jet ink for color filter comprising, by weight, 10 to 50 parts of aqueous nano pigment dispersion and 51 to 95 parts of a cold curing component.

Memory devices adapted to repair single unprogrammable cells during a program operation, and to repair columns containing unprogrammable cells during a subsequent erase operation. Programming of such memory devices includes determining that a single cell is unprogrammable and repairing the single cell, and repairing a column containing the single cell responsive to a subsequent erase operation.

A method of preparing a simple ceramic ingot of a spent filter having radioactive cesium trapped therein, and a ceramic ingot of a spent filter having improved properties such as leach resistance, thermal stability, and cesium content are provided. The method includes grinding and mixing a spent filter having cesium trapped therein, adding a solidifying agent, and sintering the spent filter. The method of preparing a ceramic ingot of a spent filter can be useful in preparing the ceramic ingot of the spent filter from only the spent filter by means of simple grinding and sintering, and in preparing the ceramic ingot of the spent filter by adding a small amount of a solidifying agent. The ceramic ingot of the spent filter has a high density and improved thermal stability, and shows improved leach resistance since a leach rate of a radioactive material is remarkably low. Therefore, the spent filter having radioactive cesium trapped therein can be effectively used to prepare a stable ceramic ingot.

The present invention relates to methods for preparing a degradable polymer network. The methods for preparing a degradable polymer network comprise a) preparing a polymer composition comprising monomers of cyclic carbonates and/or cyclic esters and/or linear carbonates and/or linear esters and/or cyclic ethers and/or linear hydroxycarboxylic acids at a temperature between 20° C. and 200° C.; b) adding a cross-linking reagent comprising at least one double or triple C—C bond and/or a cross-linking radical initiator; c) processing the polymer composition (that contains the crosslinking reagent into a desired shape; d) Crosslinking by irradiating the mixture. Further, the present invention relates to a degradable polymer network. Furthermore, the present invention relates to the use of the degradable polymer network.

A crosslinkable curing super-branched polyester and the cured product and the preparation method thereof are disclosed. The super-branched polyester has high refractive index and comprises a compound represented by the following structural formula (I). In the formula (I), HBP is the backbone of the super-branched polyester; both a and b are positive integers; the sum of a and b is less than or equal to n; n is more than or equal to 10 and less than 80. In the super-branched polyester, A is represented by formula (II) and N is represented by formula (III), wherein R is methyl or hydrogen atom; the mole ratio of N relative to the total mole of A and N is more than 30 mol %, and the ratio of the total mole of A and N relative to the product of the total mole of HBP backbone and n is more than 0.5 and less than or equal to 1.

A process for the preparation of polymer lattices comprising polymer nanoparticles by a photo-initiated heterophase polymerization includes preparing a heterophase medium comprising a dispersed phase and a continuous phase and at least one of at least one surfactant, at least one photoinitiator, and at least one polymerizable monomer. The at least one polymerizable monomer is polymerized by irradiating the heterophase medium with electromagnetic radiation so as to induce a generation of radicals. The at least one photoinitiator is selected from compounds comprising at least one phosphorous oxide group (P═O) or at least one phosphorous sulfide (P═S) group. The irradiating of the heterophase medium is effected so that a ratio of an irradiated surface of the heterophase medium to a volume of the heterophase medium is at least 200 m−1.

Methods or preparing para-xylene from biomass by carrying out a Diels-Alder cycloaddition at controlled temperatures and activity ratios. Methods of preparing bio-terephthalic acid and bio-poly(ethylene terephthalate (bio-PET) are also disclosed, as well as products formed from bio-PET.

A fluorographene and preparation method thereof are provided. For the said fluorographene, the fraction of F is 0.5

The present disclosure relates to a process for separating a fluoroolefin from a mixture comprising hydrogen fluoride and fluoroolefin, comprising azeotropic distillation both with and without an entrainer. In particular are disclosed processes for separating any of HFC-1225ye, HFC-1234ze, HFC-1234yf or HFC-1243zf from HF.

The present invention relates to a process for separating chlorinated methanes utilizing a dividing wall column. Processes and manufacturing assemblies for generating chlorinated methanes are also provided, as are processes for producing products utilizing the chlorinated methanes produced and/or separated utilizing the present process(es) and/or assemblies.

The invention relates to a process for the preparation of formula (I) which process comprises pyrolyzing a compound of formula (II) wherein X is chloro or bromo, and to compounds which may be used as intermediates for the manufacture of the compound of formula I and to the preparation of said intermediates.

The subject of the invention is a process for the preparation of fluoroolefin compounds. It relates more particularly to a process for manufacturing a (hydro)fluoroolefin compound comprising (i) bringing at least one compound comprising from three to six carbon atoms, at least two fluorine atoms and at least one hydrogen atom, provided that at least one hydrogen atom and one fluorine atom are located on adjacent carbon atoms, into contact with potassium hydroxide in a stirred reactor, containing an aqueous reaction medium, equipped with at least one inlet for the reactants and with at least one outlet, in order to give the (hydro)fluoroolefin compound, which is separated from the reaction medium in gaseous form, and potassium fluoride, (ii) bringing the potassium fluoride formed in (i) into contact, in an aqueous medium, with calcium hydroxide in order to give potassium hydroxide and to precipitate calcium fluoride, (iii) separation of the calcium fluoride precipitated in step (ii) from the reaction medium and (iv) optionally, the reaction medium is recycled after optional adjustment of the potassium hydroxide concentration to step (i).

The present invention provides a method for separating halocarbons. In particular, the invention provides a method for separating halogenated olefin impurities from 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) using a solid adsorbent, particularly activated carbon. More particularly the invention pertains to a method for separating 2-chloro-3,3,3-trifluoro-propene (HCFO-1233xf) from HCFC-244bb, which are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

A process for making a fluorinated olefin having the step of dehydrochlorinating a hydrochlorofluorocarbon having at least one hydrogen atom and at least one chlorine atom on adjacent carbon atoms, preferably carried out in the presence of a catalyst selected from the group consisting of (i) one or more metal halides, (ii) one or more halogenated metal oxides, (iii) one or more zero-valent metals/metal alloys, (iv) a combination of two or more of the foregoing.

A composition and method demulsify a produced emulsion from anionic surfactants and polymer (SP) and alkali, surfactants, and polymer (ASP). The produced emulsion is demulsified into oil and water. In one embodiment, the composition includes a surfactant. The surfactant comprises a cationic surfactant, an amphoteric surfactant, or any combinations thereof.

The invention is drawn to fluid concentrate formulations of fatty acid monoethanolamides comprising (a) about 71-76% by weight of one or more C8-C22 fatty acid monoethanolamides, (b) about 15-17% by weight of water, and (c) about 10-12% by weight of one or more hydrotropes, based on the fluid formulation, wherein the fluid formulation is homogeneous, pumpable and color stable at a temperature of less than 55° C. A preferred embodiment is drawn to fluid concentrate formulations of cocamide monoethanolamide (CMEA) consisting of (a) about 71-76% by weight of CMEA, (b) about 15-17% by weight of water, and (c) about 10-12% by weight of glycerol, based on the fluid formulation. Methods of preparing the fluid concentrate formulations mulations are also disclosed. The fluid concentrate formulations of fatty acid monoethanolamides are useful in the preparation of cosmetic and pharmaceutical compositions.

This invention provides a method related to the preparation of derivatives of poly(ethylene glycol), wherein the method comprises increasing the pH of an aqueous composition comprising a poly(ethylene glycol) bearing a —O—(CH2)n—CO2R3 functional group to result in an aqueous composition comprising a poly(ethylene glycol) bearing a —O—(CH2)n—CO2H functional group, wherein R3 is alkyl and (n) in each instance is 1-6.

Oil-water dispersions and emulsions derived from petroleum industry operations are demulsified and clarified using anionic polymers. Formation of such oil-water dispersion and emulsions is inhibited and mitigated using the anionic polymers. The anionic polymers comprise: A) 2-80% by weight of at least one C3-C8 α,β-ethylenically unsaturated carboxylic acid monomer; B) 15-80% by weight of at least one nonionic, copolymerizable α,β-ethylenically unsaturated monomer; C) 1-50% by weight of one or more of the following monomers: C1) at least one nonionic vinyl surfactant ester; or C2) at least one nonionic, copolymerizable α,β-ethylenically unsaturated monomer having longer polymer chains than monomer B), or C3) at least one nonionic urethane monomer; and, optionally, D) 0-5% by weight of at least one crosslinker.

A method of making cerium-containing metal oxide nanoparticles in non-polar solvent eliminates the need for solvent shifting steps. The direct synthesis method involves: (a) forming a reaction mixture of a source of cerous ion and a carboxylic acid, and optionally, a hydrocarbon solvent; and optionally further comprises a non-cerous metal ion; (b) heating the reaction mixture to oxidize cerous ion to ceric ion; and (c) recovering a nanoparticle of either cerium oxide or a mixed metal oxide comprising cerium. The cerium-containing oxide nanoparticles thus obtained have cubic fluorite crystal structure and a geometric diameter in the range of about 1 nanometer to about 20 nanometers. Dispersions of cerium-containing oxide nanoparticles prepared by this method can be used as a component of a fuel or lubricant additive.

The present invention relates to a process for preparing cyclic compounds having at least eight carbon atoms and at least one keto group, to the cyclic compounds obtained by this process and to the use thereof, in particular as fragrance or for providing a fragrance.

The invention relates to a process for rectificative separation of compositions of matter containing diastereomers of 2-isopropyl-5-methylcyclohexanol by using ionic liquids as extractants.

The present invention is directed to processes for the recovery of ethanol from a crude ethanol product obtained from the hydrogenation of acetic acid using a low energy process. The crude ethanol product is separated in one or more columns. At least one of the columns is operated at a controlled pressure to enhance separation of ethanol and organics. In one embodiment, there are at least two columns that operate at controlled pressures.

Disclosed herein are processes for alcohol production by reducing an esterification product, such as ethyl acetate. The processes comprise esterifying acetic acid and an alcohol such as ethanol to produce an esterification product. The esterification product may be recovered using an extractive separation. The esterification product is reduced with hydrogen in the presence of a catalyst to obtain a crude reaction mixture comprising the alcohol, in particular ethanol, which may be separated from the crude reaction mixture.

The present invention relates to a method for preparing menthone, starting from isopulegol, using specific homogeneous catalysts.

A para-methoxy protected benzaldehyde useful in preparation of treprostinil, and of formula: (Formula (1)) is prepared by subjecting to Claisen re-arrangement a substituted benzaldehyde of formula (1a): (Formula (Ia)) to form the m-hydroxy-substituted benzaldehyde of formula (1b): (Formula (Ib)) and then reacting compound (1b) with a p-methoxybenzyl (PMB) compound to form a PMB-substituted benzaldehyde of formula (1).

Disclosed is a method for preparing a compound of Formula 1 wherein Q and Z are as defined in the disclosure comprising distilling water from a mixture comprising a compound of Formula 2, a compound of Formula 3, a base comprising at least one compound selected from the group consisting of alkaline earth metal hydroxides of Formula 4 wherein M is Ca, Sr or Ba, alkali metal carbonates of Formula 4a wherein M1 is Li, Na or K, 1,5-diazabicyclo[4.3.0]non-5-ene and 1,8-diazabicyclo[5.4.0]undec-7-ene, and an aprotic solvent capable of forming a low-boiling azeotrope with water. Also disclosed is a method for preparing a compound of Formula 2 comprising (1) forming a reaction mixture comprising a Grignard reagent derived from contacting a compound of Formula 5 wherein X is Cl, Br or I with magnesium metal or an alkylmagnesium halide in the presence of an ethereal solvent, and then (2) contacting the reaction mixture with a compound of Formula 6 wherein Y is OR11 or NR12R13, and R11, R12 and R13 are as defined in the disclosure. Further disclosed is a method for preparing a compound of Formula 7 wherein Q and Z are as defined in the disclosure, using a compound of Formula 1 characterized by preparing the compound of Formula 1 by the method disclosed above or using a compound of Formula 1 prepared by the method disclosed above.

A process for preparing a particle defoamer. The particle defoamer of 55%-75% of a carrier, 15%-35% of a silicone emulsion, 3%-10% of a texturing agent and 2%-10% of a solvent, based on the total weight of the particle defoamer; the process for preparing the particle defoamer is: (1)first adding a carrier A1 into a mixer, and then adding thereto a silicone emulsion B1, and stirring uniformly; (2)adding a carrier component A2 to the mixture obtained in (1), and stirring uniformly; (3)adding a silicone emulsion B2 to the mixture obtained in (2), and, after uniformly stirring, adding the solvent thereto and stirring uniformly; and (4)pelleting and drying by baking the mixture obtained in(3), so as to produce the product.

The present invention relates to I- and II-type crystals of L-α-glyceryl phosphoryl choline, and to a method for preparing same. More particularly, the present invention relates to noble I- and II-type anhydride crystals of L-α-glyceryl phosphoryl choline, which have a higher purity than conventional liquid L-α-glyceryl phosphoryl choline, and one advantage of which is that formulations and dosages of pharmaceuticals are easily modified, and another advantage of which is that the hygroscopicity of the crystals are much lower than that of conventional polymorphic crystals, providing excellent stability during storage. The present invention also relates to a method for preparing the I- and II-type crystals of L-α-glyceryl phosphoryl choline. The I-type crystal of L-α-glyceryl phosphoryl choline is characterized by having an onset temperature of 147° C. and an absorption peak of 150° C. based on differential scanning calorimeter (DSC) analysis, and by having diffraction patterns where 2θ-diffraction angles are 9.8±0.2°, 12.0±0.2°, 14.3±0.2°, 15.8±0.2°, and 19.6±0.2° based on X-ray diffraction (XRD) analysis. The II-type crystal of L-α-glyceryl phosphoryl choline is characterized by having an onset temperature of 62° C. and an absorption peak of 66° C., and an onset temperature of 141° C. and an absorption peak of 145° C. based on DSC analysis, and having diffraction patterns where 2θ-diffraction angles are 10.3±0.2°, 12.2±0.2°, 13.4±0.2°, 14.8±0.2°, and 20.6±0.2° based on XRD analysis.

Fluoroalkyl alkyl carbonates and fluorosubstituted carbamates which are suitable as additives or solvents in lithium ion batteries are prepared from fluoroalkyl fluoroformates and the respective alcohol or amine. Methanol is the preferred alcohol, dimethylamine and diethylamine are preferred amines. Fluoromethyl methyl carbonate is the preferred compound to be produced. Fluoroalkyl fluoroformates can be prepared from aldehydes and carbonyl fluoride.