Showing papers on "Boron trifluoride published in 1969"
TL;DR: Tri-O-acetyl-D-glucal undergoes complete reaction with alcohols in benzene solution in the presence of boron trifluoride to give 4,6-di-OðOðAðEðDÞÞ −2,3-dideoxy-α-DÒÞ−EðE Þ−hex-hex-2-enopyranosyl as discussed by the authors, which can be used to prepare the known crystalline ethyl αglucoside easily and in greatly improved
Abstract: Tri-O-acetyl-D-glucal undergoes complete reaction with alcohols in benzene solution in the presence of boron trifluoride to give 4,6-di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranosides. The α-anomers predominate (ca. 90%), and the method can be used to prepare the known crystalline ethyl α-glucoside easily and in greatly improved yield. Other alkyl glycosides have been prepared similarly, and the procedure has afforded means of obtaining the cholesteryl analogue and the disaccharide derivative 6-O-(4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranosyl)-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose. Tri-O-acetyl-D-glucal again gave the 2,3-unsaturated glycosides on treatment with acetals in the presence of boron trifluoride; no evidence was obtained for the formation of branched-chain products produced by additions to the double bond.
179 citations
96 citations
TL;DR: The procedure of Metcalfe et al. as discussed by the authors for the preparation of fatty acid methyl esters, using boron trifluoride as catalyst, is shown to be suitable for use with oils containing fatty acids of unusual structures, such as conjugated unsaturation, hydroxyl or epoxy groups, and cyclopropenes in addition to oils with only the common acids.
Abstract: The procedure of Metcalfe et al. (3) for the preparation of fatty acid methyl esters, using boron trifluoride as catalyst, is shown to be suitable for use with oils containing fatty acids of unusual structures, such as conjugated unsaturation, hydroxyl or epoxy groups, and cyclopropenes in addition to oils with only the common acids. In some cases, boron trifluoride was less destructive to unusual groups than conventional mineral acid catalysts; in others, derivatives were formed that were suitable for quantitation in subsequent gas chromatographic analysis.
60 citations
33 citations
TL;DR: The backbone rearrangement leading to 13(17)-enes (e.g. III) occurs when cholest-5-ene is heated with toluene-p-sulphonic acid in acetic acid, and also when 5,6α-epoxy-5α-cholestane (VII) is treated with boron trifluoride.
28 citations
TL;DR: The electronic structure of boron trifluoride has been calculated ab initio by using extended basis sets of Gaussian type atomic orbitals as mentioned in this paper, and the minimum energy situation was found at 1.306 a (experimental 1.31 a).
Abstract: The electronic structure of boron trifluoride has been calculated ab initio by using extended basis sets of Gaussian type atomic orbitals. By variation of the B-F bond length a minimum energy situation was found at 1.306 a (experimental 1.31 a). Calculations on the pyramidal (reorganised) form of the molecule led to a reorganisation energy of 34.2 kcal mole−1. The π localisation energy was found to be 50.4 kcalmole−1. Both the latter energy and the π charge distribution are in good agreement with results from a previous Pariser-Parr-Pople calculation. The calculated quantities are used to discuss the energetics of donor-acceptor complex formation.
25 citations
23 citations
TL;DR: Commercial boron trifluoride ethyl ether functions as an effective catalyst in the synthesis of a number of alkyl esters of p-aminobenzoic acid.
22 citations
TL;DR: In this paper, three epoxides (IX, XIX and XX) prepared from the eudesm-4-enes (VIII and XVIII) on treatment with BF 3 -etherate have been found to undergo skeletal rearrangement resulting in the formation of a number of ketones.
21 citations
18 citations
TL;DR: In this paper, the electronic structure of BF3 was calculated by a self-consistent field method using an extended set of Gaussian-type basis functions, which was then used to calculate its electronic structure.
Abstract: The electronic structure of BF3 has been calculated by a self-consistent field method using an extended set of Gaussian-type basis functions.
TL;DR: In this article, a series of complexes of boron trifluoride with amine donor molecules (e.g., BF3·NH3) were investigated and the activation energies for the reorientation process were derived from the temperature dependence of the linewidths.
Abstract: Broad-line n.m.r. investigations of a series of complexes of boron trifluoride with amine donor molecules (e.g., BF3· NH3) reveal the presence of molecular motion in the solid state. From the temperature dependence of the linewidths, activation energies are derived for the reorientation process. The observed values of the second moments of the absorption signals are compared with theoretical values calculated from the known X-ray structures assuming motion of different parts of the complexes. The motions are discussed in relation to the crystal and molecular structures of the various complexes.
Patent•
20 Mar 1969
TL;DR: SODIUM BOROHYDRIDE in TetraHYDROFURAN can be PREPARED without HANDLING the GAS by TREATINGS as discussed by the authors.
Abstract: SOLUTIONS OF DIBORANE IN TETRAHYDROFURAN CAN BE PREPARED WITHOUT HANDLING THE GAS BY TREATINGSUSPENSIONS OF SODIUM BOROHYDRIDE IN TETRAHYDROFURAN WITH BORON TRIFLUORIDE, FOLLOWED BY DECANTING, FILTERING, OR CENTRIFUGING ITATED SODIUM FLUOBORATE. SUCH SOLUTIONS ARE NORMALLY UNSTABLE AT ORDINARY TEMPERATURES, UNDERGOING REDUCTIVE CLEAVAGE OF THE SOLVENT. CONSEQUENTLY, THEY CANNOT BE STORED FOR ANY APPRECIABLE TIME OF SHIPPED ANY APPRECIABLE DISTANCE. HOWEVER, THESE SOLUTIONS ARE STABILIZED TOWARD SUCH REDUCTIVE CLEAVAGE BY BY UTILIZING IN THE SYNTHESIS A SLIGHT EXCESS OF SODIUM BOROHYDRIDE OR OTHER IONIC BOROHYDRIDES. THESE DICOVERIES NOW MAKE PRACTICAL THE MANUFACTURE, SHIPPING, STORING AND APLICATION OF SUCH SOLUTIONS OF DIBORANE IN TETRAHYDROFURAN, HIGHLY USEFUL FOR HYDROBORATIONS AND HYDROGENATIONS.
TL;DR: In this paper, the pπ-conjugation energies of a number of aromatic amines, ethers and sulphides have been determined, and good agreement in the values obtained when using aluminium bromide, aluminium chloride, boron trifluoride and gallium trichloride as acceptors proves the correctness of the concepts which lie at the basis of the above method.
TL;DR: In this paper, the reaction of methyl 12,13-epoxyoctadec-9-enoate (VII) and methyl 9,10-enoxylate-12-enoxide (VIII) with BF3-etherate yielded mixtures of cyclic and unsaturated acyclic compounds.
TL;DR: Treated with boron trifluoride etherate in dioxan solution, methyl 12,13-epoxyoleate gives the 12- and 13-oxo-oleates as major products.
Patent•
02 Jul 1969
TL;DR: In this paper, the authors describe the presence of an ALKYLATED POLYHYDROXY COMPOUND and OLEFIN in the PRESENCE of a BORON TRIFLUORIDE CATALYST.
Abstract: THE PRESENCE OF ALKYLATED POLYHDROXY BENZENOID COMHAVING FROM 1 TO 4 ALKYL GROUPS OF 6 TO 100 CARBON ATOMS, PREFERABLY 6 TO 30 CARBON ATOMS, AND AT LEAST 2 HYDROXY GRUOPS, SUCH COMPOUNDS BEING PREPARED FROM THE APPROPRIATE POLYHYDROXY COMPOUND AND OLEFIN IN THE PRESENCE OF A BORON TRIFLUORIDE CATALYST, PROVIDE HIGH TEMPERATURE OXIDATION PROTECTION TO LUBRICATING OILS AND OTHER ORGANIC MATERIALS.
TL;DR: In this article, the boron trifluoride catalysed reaction of 1-deoxy-D-arabino-hex-1-enopyranose (2-hydroxyglucal) esters with alcohols was investigated.
Abstract: The boron trifluoride catalysed reaction of 1-deoxy-D-arabino-hex-1-enopyranose (2-hydroxyglucal) esters with alcohols afforded alkyl 3-deoxy-D-erythro-hex-2-enopyranoside esters with the α-anomers predominating; several have been isolated crystalline in good yield. Alternatively, crystalline β-anomers have been obtained by the uncatalysed alcoholysis of 2,4,6-tri-O-benzoyl-3-deoxy-1-O-trichloroacetyl-α-D-erythro-hex-2-enose. The nuclear magnetic resonance and optical rotatory dispersion characteristics of the members of the anomeric pairs of unsaturated glycosides are compared.
TL;DR: In this article, a method for opening the epoxide ring of 12-methoxypodocarpa-8,11,13-trien-19-oic acid was proposed.
Abstract: Selective epoxidation of the methoxy alkene mixture (IX) from oxidative decarboxylation of 12-methoxypodocarpa-8,11,13-trien-19-oic acid (I) provides a method of obtaining a high yield of the exocyclic alkene (VII) from the mixture. Isolation of the 3α,4α-epoxide (X) during the epoxidation allows the formation of C 3 oxygenated derivatives of 12- methoxypodocarpa-8,11,13-trien-19-oic acid. Methods for opening the epoxide ring of (X) and of the 4α,5α- and 4α,19-epoxides, (XI) and (XII), have been examined, and the structures of the products from rearrangement of each epoxide with boron trifluoride have been assigned.
TL;DR: In this paper, the reaction of tricarbonyl(trispyridine)chromium with 1-and 2-hydroxyindanes in the presence of boron trifluoride etherate gave in each case pure cis-tricarbonyls(hydroxy-indane) chromium together with some pentacarbonyll(pyridine)-chromium.
Abstract: Reaction of tricarbonyl(trispyridine)chromium with 1- and 2-hydroxyindanes in the presence of boron trifluoride etherate gave in each case pure cis-tricarbonyl(hydroxyindane)chromium together with some pentacarbonyl(pyridine)chromium. 1-Methoxyindane also gave exclusively cis-tricarbonyl compound and the reactions have been shown to be kinetically controlled. These results are compared with the similar stereospecificity of the Simmons–Smith reaction with some hydroxy- and alkoxy-cyclic olefins. The early stages of the reaction of hexacarbonylchromium with hydroxy- and methoxy-indanes also appear to be partially kinetically controlled and the formation of cis-isomers is preferred. The reactions of tricarbonyl(trispyridine)chromium with other substituted indanes are discussed.
TL;DR: In this article, amides are cleaved by methanolic boron trifluoride to the volatile methyl esters, which are suitable for gas chromatography.
Abstract: Amides are cleaved by methanolic boron trifluoride to the volatile methyl esters, which are suitable for gas chromatography.
TL;DR: The reaction of acyl azides with trifluoride or boron trichloride leads to instable adducts of structure as mentioned in this paper, which are then used to identify urethanes.
Patent•
28 Jan 1969
TL;DR: In this article, the authors describe compositions of mineral lubricating oil, zinc dihexyl phosphorodithionate and products obtained by reacting polypropylenes and polybutylene with phenol in the presence of boron trifluoride/phenol complexes.
Abstract: 1,212,462. Lubricants. MOBIL OIL CORP. 28 Jan., 1969, No. 4631/69. Heading C5F. [Also in Division C3] Lubricating oil compositions comprise as dispersant a polyalkenyl substituted phenol prepared by reacting a phenolic compound with a polyalkene of molecular weight 600 to 3000 in the presence of a boron trifluoride complex. Specified phenols are phenol, resorcinol, hydroquinone, catechol, cresol, xylenol, hydroxydiphenyl, benzylphenol, phenylethylphenol, phenolic resins, methylhydroxydiphenyl, guaiacol, naphthols and alkyl- and aryl-naphthols, anthranol, phenanthrol, catechol monomethyl ether, phenoxyphenol, chlorophenol and phenol sulphides. Specified polyalkenes are polypropylene, polybutylene and polyamylene. The catalyst may be an etherate, phenolate or phosphate complex of boron trifluoride. Examples describe compositions of mineral lubricating oil, zinc dihexyl phosphorodithionate and products obtained by reacting polypropylenes and polybutylene with phenol in the presence of boron trifluoride/phenol complexes.
TL;DR: Boron 10 absorption cross sections from counting ratios measurements of boron trifluoride proportional counter used to monitor neutron fluxes as mentioned in this paper, which is used for counting ratios measurement.