Mixture Of Diols Research Articles

Synthesis and properties of homo- and copolycyanurates

Four homopolycyanurates were synthesized by stirred interfacial polycondensation of 2-diethyl-amino-4,6-dichloro-s-triazine with each of three aromatic diols viz. bisphenol-A (BPA), bisphenol-C (BPC), bisphenol-S (BPS) and phenolphathalein (Ph). Four copolycyanurates were synthesized using each of the following mixtures of diols: (BPA + BPC), (BPA + BPS), (BPA + Ph) and (BPC + BPS). The polymers yields were in the range 48–80%. They were characterized by density, viscosity measurements, i.r. spectra, solubility tests and thermogravimetric analysis. The polymers had reduced viscosities in the range of 0.17–0.37 dl/g in chloroform at 30°. All the polymers were amorphous and soluble in chlorinated solvents. Homopolycyanurate derived from BPA and copolycyanurate derived from (BPA + BPC) showed greater thermal stability than the others.

Nitro‐ and fluoropolyformals. III. Copolyformals from mixtures of fluoro‐ and nitro‐α,ω‐diols

AbstractPolyformals of fluoro‐, nitramine‐, and C‐nitrodiols show widely differing properties with respect to glass transition temperature, melting transition, and solubility. Polymers with desirable combinations of these properties, e.g., low Tg, high nitro content, and good solubility in polar solvents, were expected to result from acid‐promoted copolycondensation of appropriate mixtures of diols with formaldehyde. A series of such condensations were carried out and the polymers obtained from binary mixtures of fluoro‐ and nitrodiols, different nitrodiols, and fluoro‐ or nitrodiols and carboranediols, were characterized by GPC, 1H‐NMR, and DSC analysis.

ChemInform Abstract: Chemistry of the S=O Bond. Part 11. trans,trans‐4,6‐Di‐tert.‐butyl‐trans‐5‐methyl‐1,3,2‐dioxathiane 2‐Oxide (III) and cis,cis‐4,6‐Di‐tert.‐butyl‐cis‐5‐methyl‐1,3,2‐dioxathiane 2‐Oxide (IV), Synthesis and Crystal Structure Determination.

AbstractReduction of dione (I) leads to a diastereoisomeric mixture of diols (II) with no (3R,4S,5S)‐diastereomer formed because reaction of the mixture with SOCl2 leads to (III) (space group Pnam, Z=4), (IV) (P21/c, Z=4) (both resulting from the (3R,4R,5S)‐diol), and (V) which is either a mixture or one of the 2‐oxide isomers (not distinguishable).

ChemInform Abstract: Enzymes in Organic Synthesis. Part 2. Prostaglandins and Prostaglandin Intermediates. Part 23. Synthesis of Enantiomerically Pure Prostaglandin Intermediates by Enzymatic Hydrolysis of (1SR,5RS,6RS,7RS)‐7‐Acetoxy‐6‐acetoxymethyl‐2‐oxabicyclo(3.3.0)octan‐3‐one.

AbstractEnzymatic hydrolysis of the title compound (I) leads to a mixture of enantiomeric diols, monoacetates and diacetates which are separated chromatographically.

Preparation and biocompatibility of novel polar-nonpolar networks

Mixed polar-nonpolar urethane networks have been prepared by crosslinking various mixtures of polyisobutylene diols (HO-PIB-OH) and polar polytetrahydrofuran diols (HO-PTHF-OH) with stoichiometric quantities of a triisocyanate. Essentially complete crosslinking was demonstrated by very low (<4%) sol fractions in benzene and THF. The mixed networks were biocompatible and had less tissue response than pure PIB as evaluated by bacterial and histological analysis after 11 weeks of implantation at the following sites: dorsal neck muscle, abdominal cavity and near the abdominal aorta.

Chemistry of the SO bond. Part 11. trans,trans-4,6-Di-t-butyl-trans-5-methyl-1,3,2-dioxathiane 2-oxide and cis,cis-4,6-di-t-butyl-cis-5-methyl-1,3,2-dioxathiane 2-oxide, synthesis and crystal structure determination

Reduction by LiAlH4 of 2,2,4,6,6-pentamethylheptane-3,5-dione gives a mixture of diastereoisomeric diols, which upon cyclisation with thionyl chloride yields a mixture of isomeric 4,6-di-t-butyl-5-methyl-1,3,2-dioxathiane 2-oxide. From the distribution of the latter mixture, a small, but distinct stereoselectivity of the dione reduction is inferred, which in turn suggests a preference of the reacting dione for an extended conformation.Single crystal X-ray determinations have been performed on the two title compounds (components of the cyclic sulphite mixture) to establish their structure, conformation and geometry. The geometries are compared with currently available population averages of cyclic sulphites. The high substitution present in the title compounds does not show in the C–O–S(O)–O–C region of the ring, but reveals itself markedly in the C(4)–C(6) region and in the substituents.

Host: Guest chemistry of diaza-18-crown-6: Selective precipitation from mixtures of oligohydroxy phenols and the structures of five host: Guest complexes

Diaza-18-crown-6 (1,4,10,13-tetraoxa-7,16-diaza-cyclo-octadecane) selectively precipitates as a 1,4-dihydroxybenzene-complex from a mixture of isomeric phenols and as a 2,6-dihydroxynapthalene-complex from mixtures of isomeric diols. These selective precipitations are discussed in terms of structure and solubility of the host-guest complexes and phenol acidity. The crystal structures of diaza-18-crown-6 with guestsp-nitrophenol (2: 1), 2,4-dinitroaniline (2: 1), 5,5-diethylbarbituric acid (2: 1), salicylaldoxime (2: 1) and 1,4-dihydroxybut-2-yne (1: 1) are reported.

Analysis of 2,2-di( p-oligooxyethylenephenyl)propane by gas chromatography and gas chromatography—mass spectrometry

Gas chromatography and gas chromatography—mass spectrometry were used to analyse polydisperse mixtures of diols containing up to ten oxyethylene groups. The products were analysed as their trimethylsilyl derivatives. Arithmetic retention indices were determined for the diol homologues. The mass spectra of the trimethylsilyl derivatives of the compounds investigated are discussed.

Homochiral Ketals in Organic Synthesis. Enantioselective Synthesis of (4S, 5S)-4,5-Dihydroxycyclopent-2-En-1-One Isopropylidine Ketal

Abstract The title compound has been synthesized in 17% yield over six steps from 2-cyclopenten-1-one. The key step is catalytic osmylation of 4-bromo-2-cyclopenten-1-one 1,4-di-O-benzyl-D-threitol ketal to produce a chromatographically separable mixture of diastereomeric diols.

Excess molar volumes of binary mixtures of diols and water

Volumes d'exces des melanges eau-butaneiols-1,2, -1,3 et -1,4, propanediol-1,3 et pentanediol-1,5

ChemInform Abstract: Studies in the Synthesis and Biosynthesis of C‐Nucleosides

Abstract The naturally occurring C-nucleosides show marked antiturnour and antiviral properties. We have developed, over a period of years, a general synthetic route to C-nucleosides by way of acetylenic intermediates. Tri-O-benzyl-D-ribofuranose (1) reacts with acetylenic Grignard reagents to give mixtures of D-allo and D-altro diols. The latter, on ring closure by means of toluene-p-sulphonyl chloride in pyridine, gives derivatives, (2) or (3), of β-D-ribofuranosylethyne in ∼50% yield from (1).

Dependence of chain conformation and solution thermodynamics on composition for poly(ortho ester)s prepared from ketene acetals and mixtures of diols

AbstractThe solution properties of a series of random copolymers prepared from ketene acetals with mixtures of diols have been characterized by dilute solution light scattering, chromatographic, and viscometric techniques. Five solvents with refractive indices ranging from 1.4 to 1.5 were used to obtain the correct weight average molecular weight. Changes in the unperturbed radius of gyration, obtained by combined size exclusion chromatography and low‐angle light scattering techniques, parallelled that predicted by simple considerations of changes in repeat unit size. Thus the relative contributions of differing copolymer–solvent interactions and changing unperturbed radii of gyration to the hydrodynamic volume of random copolymers of different compositions were evaluated.

Studies in the Synthesis and Biosynthesis of C-Nucleosides

Abstract The naturally occurring C-nucleosides show marked antiturnour and antiviral properties. We have developed, over a period of years, a general synthetic route to C-nucleosides by way of acetylenic intermediates. Tri-O-benzyl-D-ribofuranose (1) reacts with acetylenic Grignard reagents to give mixtures of D-allo and D-altro diols. The latter, on ring closure by means of toluene-p-sulphonyl chloride in pyridine, gives derivatives, (2) or (3), of β-D-ribofuranosylethyne in ∼50% yield from (1).

Total synthesis of cleomiscosin A, a coumarinolignoid.

The coumarinolignoid cleomiscosin A (1), having antitumor activity, has been synthesized via the keto-ester (10), which was prepared from readily available starting materials (6 and 9). Removal of the methoxymethyl group of 10 followed by reduction with lithium borohydride gave a mixture of diols (12a, b). Treatment of 12a, b with 5% sulfuric acid in acetic acid provided cleomiscosin A monoacetate (14) and subsequent hydrolysis with sodium hydroxide afforded 1.

Studies of chromens. Part 3. Routes to 2,2-dimethylchroman-3-ones and 4-ethyoxycarbonyl-2,2-dimethylchromens. Synthesis of a stable chromenopyrazolinone

2,2-Dimethyl-3,4-epoxychroman (6a) was converted into 2,2-dimethylchroman-3-one which readily underwent ethoxycarbonylation to 4-ethoxycarbonyl-2,2-dimethylchroman-3-one (5c). The derived 4-ethoxycarbonyl-2,2-dimethylchromen (1b) reacted with hydrazine to give the pyrazolidinone (4a), oxidation of which gave the stable pyrazolinone (11). Lead tetra-acetate acetoxylation of 7-methoxy-2,2-dimethylchroman-4-one, followed by metal hydride reduction, afforded the 3,4-diol as a mixture of isomers. The relative proportions of cis and trans isomers could be varied from 1:1 to 5:1, respectively, by the choice of reducing conditions. Acid-catalysed dehydration of the diol mixture gave 7-methoxy-2,2-dimethylchroman-3-one (5b). This was unstable and could not be ethoxycarbonylated, but 4-ethoxycarbonyl-7-methoxy-2,2-dimethylchroman-3-one (5d)/(1j) was obtained by a standard synthesis.

Long‐chain phenols: XX. Synthesis of oxidative degradation products from the methylated component phenols ofAnacardium occidentale and other phenolic lipids: Confirmation of the structure of the parent phenols and of a related material

AbstractA general procedure for the determination of the first double bond position in the side‐chain of a phenolic lipid has been investigated and, in the first place, the phenols of natural cashew nut‐shell liquid (Anacardium occidentale) have been examined. An improved oxidative degradation procedure has been applied consisting of methylation by the phase transfer procedure, hydroxylation with performic acid and oxidation of the mixture of vicinal diols with periodic acid (Malaprade reaction) followed by reduction of the aldehyde fragments with sodium borohydride. The aromatic moieties from the 15∶1, 15∶2 and 15∶3 constituents of cardanol methyl ether, cardol dimethyl ether and dimethyl anacardate were shown to be 8‐(3‐methoxyphenyl)octan‐1‐ol, 8‐(3,5‐dimethoxyphenyl)octan‐1‐ol and 6‐(8‐hydroxyocyl)salicylate methyl ether, respectively. The first two octanols were identical to synthetic materials, thus confirming the 8‐position for the first double bond in the side‐chain of cardanol methyl ether and cardol dimethyl ether constituents. Methyl 6‐(8‐hydroxyoctyl)salicylate relationship in a series of synthetic reference materials of log (retention time) to the methylene chain length. The synthetic acids 8‐(3‐methoxyphenyl)octanoic acid, 8‐(3,5‐dimethoxyphenyl)octanoic acid and 6‐(7‐carboxyheptyl)salicylic acid methyl ether have been obtained pure for the first time and correspond to the oxidation products of the aromatic aldehyde fragments from the Malaprade reaction stage. The unsaturation in peladjauol, 17∶1‐bishomocardanol methyl ether, fromPentaspadon officinalis was confirmed to be at the 8‐position by the identity of the anilides of synthetic 8‐(3‐methoxyphenyl) octanoic acid and of the oxidative degradation product.

A Study of Friction Polymer Formation

Surfactant solutions in hexadecane have been studied to assess their capabilities in forming friction polymer. Only alcohols form adherent films, resistant to simple washing, on rubbing surfaces. There is no evidence of polymer formation on rubbed surfaces, even with mixtures of diacids and diols.

Lythraceous alkaloids. Part 11. Total synthesis of (±)-lythranidine

The total synthesis of (±)-lythranidine (1), a cyclophane alkaloid from Lythrum anceps Makino, has been achieved through a sequence of reactions including the following key steps : the Wittig reaction of an ylide (6) with a dialdehyde (3), epimerisation of a cis-2,6-disubstituted piperidine into the desired trans-isomer through the N-nitroso-derivative (11), amidoacetalisation of a mixture of stereoisomeric diols (12) to isolate the desired compound (13), and its partial demethylation followed by hydrolysis.

A new synthesis of four diastereoisomeric 2,6-dideoxy- dl-hexoses

The synthesis of four diastereoisomeric 2,6-dideoxy- DL-hexoses from butyl E 2,3,4-trideoxy-aldehydo- DL-hex-2-enuronate ( 2) is described. The aldehyde 2 treated with MeMgBr affords a mixture of diastereoisomeric diols 6, which after hydroxylation and Ruff degradation gives 2,6-dideoxy- DL-hexoses 13,14, 15 and 16.

Säurekatalysierte Umlagerungen von 1,5‐Dimethyl‐6‐methyliden‐tricyclo[3.2.1.02,7]oct‐3‐en‐8endo‐olen

Acid Catalysed Rearrangement of 1,5‐Dimethyl‐6‐methyliden‐tricyclo[3.2.1.02,7]oct‐3‐en‐8endo‐olsThe tricyclic alcohols 2,3,4 and 6 (Scheme 1) are synthesized by the reaction of the tricyclic ketone 1 with sodiumborohydrid or metalloorganic reagents. Their configuration at C(8) is determined by NMR. in the presence of Eu(fod)3. The exo‐attack of 1 by the nucleophil forming the endo‐alcohol is favored, the π‐electrons of C(3) = C(4) hindering the endo‐attack. On treatment with sulfuric acid in dioxane/water at 25° the tertiary alcohols yield aryl‐substituted ketones. 3 gives in 78.5% yield a mixture of the 3‐(dimethylphenyl)‐2‐butanones 12 and 13, in addition to 16.5% of (2,3,4‐trimethylphenyl)‐2‐propanon (14) (Scheme 2). The alcohols 4 and 6 yield mixtures of the 2‐(dimethylphenyl)‐3‐pentanones 19 and 20 (72%), and 2‐(dimethylphenyl)‐propiophenones 21 and 22 (68%), respectively (Scheme 2). In the case of the secondary alcohol 2 mainly products derived from hydration at the C(6), C(9) double bond are formed, namely the mixture of diols 23 and 24 (21%), and the mixture of the isomeric 2‐(dimethylphenyl)propanals 25, 26 and 27 (3%) (Scheme 3). ‐ The structures of 12–14, 19/20, 21/22, 23/24 and 25/26/27 were established by spectroscopic data. In the case of 12 and 13 the degradation of their mixture to the known 1‐(dimethylphenyl)ethanols 17/18 confirmed the assignment. ‐ The most probable mechanism for the rearrangement of 3 is shown in Schemes 4 and 5. The reaction proceeds from 3 through a, b and g to 12 and 13; 14 is formed via e, f and i. In the case of 4 and 6 only the reaction analogue to 3 → a → b → g ⇉12/13 takes place. The isomeric aldehyds 25–27 formed from 2 could have the structures s, t, and v. The former two could be generated in a similar way as 12/13 from 3, the latter one as shown in Scheme 8.