Acetylenic Alcohols Research Articles

Anthracenone ABA analogue as a potential photoaffinity reagent for ABA-binding proteins

An anthracenone analogue of abscisic acid (ABA) was synthesized as a potential photoaffinity reagent and tested for biological activity. Reaction between 10,10′-dimethoxy-9-anthrone with two equivalents of the lithiated dianion of cis-3-methylpent-2-en-4-yn-1-ol afforded an acetylenic alcohol key intermediate. Subsequent reduction of the triple bond, functional group manipulation of the side chain alcohol and deprotection of the dimethoxy protected anthrone provided anthracenone ABA analogue 7 as a potential photoaffinity reagent for ABA-binding proteins. The effect of natural ABA and the potential photoaffinity anthracenone ABA 7 on corn cell growth was determined at various concentrations. The results show that anthracenone ABA 7 is perceived as ABA-like, although producing less inhibition than ABA itself. For example, 7 at 33 μM produces approximately the same inhibition as ABA at 10 μM.

Catalytic hydrogenation of acetylenic alcohols using palladium complex of fullerene C 60

Catalytic properties of Pd–fullerene complex η 2-C 60Pd(PPh 3) 2 have been studied in the hydrogenation of acetylenic alcohols. The kinetics of the homogeneous hydrogenation has been investigated under static conditions. The catalyst quantity and the initial concentration of acetylenic alcohol have been varied. Physico-chemical properties of Pd–fullerene complex have been studied using methods of 1 H NMR, IR- and UV-spectroscopies. Using experimental results and physico-chemical investigations, the mathematical model of the process and the reaction mechanism have been offered.

Hydrogenation of acetylene alcohols with novel Pd colloidal catalysts prepared in block copolymers micelles

Hydrogenation of the triple bond of acetylene alcohols to the double one of olefin alcohols (linalool, isophytol) was studied with Pd colloids prepared in polystyrene-poly-4-vinylpyridine micelles in toluene and deposited on Al 2O 3. The high selectivity (99.8% for linalool and 99.5% for isophytol) of such catalyst is explained by durable modification of the Pd nanoparticle surface with 4-vinylpyridine units. The activity of the Pd catalyst studied is determined by high reactivity of small Pd nanoparticles. Maximum relative rate was found to be in methanol, but the highest selectivity was achieved in toluene because the latter is a selective solvent for polystyrene-poly-4-vinylpyridine micelles and provides the better accessibility of reactive sites.

Influence of Organic Additives on the Corrosion of Iron-Based Amorphous Alloys in Dilute Sulfuric Acid Solution

Abstract Some N-containing or S-containing organic substances and some acetylenic alcohols were tested as inhibitors of the corrosive attack suffered by Fe-based metallic glasses in deaerated 0.1 N sulfuric acid (H2SO4) solution at 25°C. It was verified that the specific action these compounds exerted on the corrosion process of the amorphous alloys was similar to the one these compounds exerted on polycrystalline iron. The most efficient substances were those containing a sulfur atom with available lone pairs, which chiefly inhibited the anodic reaction of both metal specimens. Owing to the chemical and physical homogeneity of the amorphous alloy, the chemisorbed inhibitor film that formed on the glassy surface was more stable and protective than that formed on the polycrystalline iron.

Influence of acetylenic derivatives on corrosion of chromium and chromium containing steels in hot acid solutions

AbstractThe influence exerted by some acetylenic alcohols (1-octyne-3-ol (OCT), 3-methyl-1-butyne-3-ol (MET), and 1-iodo-3-methyl-1-butyne-3-ol (IOD)) on the corrosion of chro mium in a 1N HCl solution at 70°C has been evaluated by electrochemical impedance spectroscopy (EIS) measurements and polarisation curve determinations. These compounds are poor inhibitors of the dissolution of chromium in acid, despite the positive benefits obtained for other transition metals such as iron or nickel. Only OCT, at a 10 mM concentration, displays a highly protective action, but this decreases rapidly during the first two hours of testing. Even the inclusion of modest amounts of chromium in iron alloys is sufficient to reduce the inhibitive effect of acetylenic alcohols. For instance, the protective action of OCT is high and persistent only for plain steel, and it decreases rapidly for alloys with chromium contents of 5–17%. The negative influence of dissolved Cr3+ ions has also been demonstrated, since their presence...

NAD+-Dependent (S)-Specific Secondary Alcohol Dehydrogenase Involved in Stereoinversion of 3-Pentyn-2-ol Catalyzed byNocardia fuscaAKU 2123

An NAD(+)-dependent alcohol dehydrogenase was purified to homogeneity from Nocardia fusca AKU 2123. The enzyme catalyzed (S)-specific oxidation of 3-pentyn-2-ol (PYOH), i.e., part of the stereoinversion reaction for the production of (R)-PYOH, which is a valuable chiral building block for pharmaceuticals, from the racemate. The enzyme used a broad variety of secondary alcohols including alkyl alcohols, alkenyl alcohols, acetylenic alcohols, and aromatic alcohols as substrates. The oxidation was (S)-isomer specific in every case. The K(m) and Vmax for (S)-PYOH and (S)-2-hexanol oxidation were 1.6 mM and 53 mumol/min/mg, and 0.33 mM and 130 mumol/min/mg, respectively. The enzyme also catalyzed stereoselective reduction of carbonyl compounds. (S)-2-Hexanol and ethyl (R)-4-chloro-3-hydroxybutanoate in high optical purity were produced from 2-hexanone and ethyl 4-chloro-3-oxobutanoate by the purified enzyme, respectively. The K(m) and Vmax for 2-hexanone reduction were 2.5 mM and 260 mumol/min/mg. The enzyme has a relative molecular mass of 150,000 and consists of four identical subunits. The NH2-terminal amino acid sequence of the enzyme shows similarity with those of the carbonyl reductase from Rhodococcus erythropolis and phenylacetaldehyde reductase from Corynebacterium sp.

Chemoenzymatic synthesis of (+)-docosa-4,15-dien-1-yn-3-ol, a component of the marine sponge Cribrochalina vasculum, and confirmation of the structure and absolute configuration of the acetylenic alcohol, by lipase-catalysed biotransformations

The (4E,15Z)- and (4E,15E)-isomers of (+)-docosa-4,15-dien-1-yn-3-ol 1, isolated from the marine sponge Cribrochalina vasculum, were synthesized in highly enantiomerically pure form by lipase-mediated biotransformation with Novozym 435, and the structure of 1 from the natural product was proved to be (4E,15Z)-docosa-4,15-dien-1-yn-3-ol 1Z. The absolute configuration of C-3 in compound (+)-1Z was assigned as S on the basis of the conversion of (+)-1Z into (R)-(–)-docosan-3-ol 17, which was also prepared from oct-7-en-3-ol 12 via biotransformation with lipase Novozym.

Silver-catalyzed cyclization of acetylenic alcohols and acids: a remarkable accelerating effect of a propargylic C–O bond

The heteroannulation catalyzed by silver salts of alkynols 1, 2 or alkynoic acids 3 is considerably enhanced by the presence of a propargylic C–O bond. This method allows for a rapid access to highly functionalized heterocycles, such as α-methylene oxolanes 4 or oxanes 5 and as γ-methylene pentanolactones 6.

New acetylenic enol ethers of glycerol from the sponge Petrosia sp.

Ten acetylenic enol ethers of glycerols, including six new compounds (1-6) and a linear acetylenic alcohol (7), have been isolated from a sponge of the genus Petrosia. The structures of the novel compounds were elucidated by spectroscopic methods. The absolute stereochemistry of 1-7 was determined by chemical transformations and the Mosher method. Some of these compounds exhibited weak cytotoxicity against a human leukemia cell-line (K-562).

Comparison of Tetrahymena and Pimephales Toxicity Based on Mechanism of Action

The toxicity data of 256 chemicals tested in both the 96-h Pimephales promelas mortality assay and the 2-d Tetrahymena pyriformis growth inhibition assay were evaluated using quantitative structure-activity relationships (QSARs). Each chemical was a priori assigned a mode of action of either narcoses or soft electrophilicity. Narcoses were separated into nonpolar narcosis, polar narcosis, monoester narcosis, diester narcosis, amine narcosis, and weak acid respiratory uncoupling based on the presence or absence of specific toxicophores. Toxicity of each narcotic mechanism was initially regressed against the 1-octanol-water partition coefficient (log K ow). The slopes of these log K ow based QSARs were observed to ascertain whether a relationship exists between the value of the slope and the reactivity of the mechanism of action. With both the fish and ciliate data nonpolar narcosis was the least reactive mechanism. It was followed by the other reversible narcoses. The soft electrophile mode was separated into the specific molecular mechanisms of: S N2 reactors, Schiff-base formers, Michael-type addition, or proelectrophilicity (precursors to Michael-type addition chemicals). These mechanisms were represented structurally by the nitrobenzenes, aldehydes, polarized α-β unsaturates (e.g., acrylates and methacrylates), and acetylenic alcohols, respectively. Electrophilic toxicity was not correlated with hydrophobicity. QSARs based on molecular orbital (MO) quantum chemical descriptors were used to improve the predictability of the electrophilic mechanisms. Relevant descriptors include average superdelocalizability (S n av) for the nucleophilic addition of the nitrobenzene; atom x and y acceptor superdelocalizability (A x ); and bond order (B x-y ) for the Michael-type addition of the acrylates; and log K ow and atom x net charge (Q x ) for the Schiff-base forming aldehydes. The pertinent descriptors for proelectrophiles were log K ow and S n av. Principal differences between the QSARs for the two biological endpoints were observed for the ester narcoses, proelectrophiles, and Schiff-base forming aldehydes.

Electronic effects of Me3SiOCR2 substituents in acetylene derivatives

The σR0 and σp parameters of Me3SiOCR2 and HOCR2 substituents at the triple bond were determined using the IR spectra of individual acetylene derivatives and their H-complexes. These parameters vary as the effective charge on the atoms of the C≡C fragment of terminal acetylenic alcohols and their trimethylsilyl ethers changes due to intermolecular interaction. The most reliable values of σR0 and σp parameters (−0.02 and −0.03, respectively) for the Me3SiOCH2 substituent were established; they indicate a sharp decrease in σ,π-conjugation of the Me3SiOCH2 substituent with the triple bond as compared to the Me3SiCH2 substituent.

Universal method for trimethylsilylation of acetylenic alcohols and glycols

A highly convenient universal method for trimethylsilylation of acetylenic alcohols and glycols via treatment by hexamethyldisilazane in the presence of benzoic acid sulphimide as a catalyst has been developed. The rate of trimethylsilylation of acetylenic alcohols is reduced from primary to secondary and to tertiary alcohols accordingly, as well as with the decreasing of hydroxyl nucleophylicity. The toxicity of trimethylsilyl acetylenic ethers, except 2-trimethylsiloxy-3-butyne, is much lower than that of original compounds.

Inhibition of acid corrosion of nickel by acetylenic alcohols

AbstractThe inhibition of nickel corrosion by means of 3-methyl-1-butyne-3-ol (H), its haloderivatives, and 1-octyn-3-ol (OCT) has been studied by solution analysis, polarisation curve recording, and electrochemical impedance spectroscopy in deaerated 1N HCl or H2SO4 solutions at 70°C. It has been found that the inhibiting effects of the additives tested are similar to those determined in the case of iron acid corrosion. It is assumed that on both metals the inhibitors form polymeric films by the same mechanism. These compounds are more efficient in the HCl than in the H2SO4 solution. Inhibitor OCT is more efficient than H, but the efficacy of the latter can be improved by replacing the acetylenic hydrogen atom with halogen atoms, chiefly iodine, which provide higher inhibition of the anodic reaction.

Inhibition of acid corrosion of nickel by acetylenic alcohols

Inhibition of acid corrosion of nickel by acetylenic alcohols

Reaction of lithium acetylides with car-3-ene-2,5-dione

The reaction of car-3-ene-2,5-dione (1), an oxidation product of (+)-car-3-ene, with lithium acetylides proceeds stereospecifically, but not regioselectively, to give only mixtures of regioisomeric acetylenic alcohols with thesyn-orientation of the hydroxy group.

Preparation of methyl cis-9, trans-11- and trans-9, trans-11-octadecadienoate-17,17,18,18-d 4, two of the isomers of conjugated linoleic acid

A multi-step synthesis was used to prepare the cis-9, trans-11- and trans-9, trans-11-isomers (in a ratio of 46/54) of conjugated linoleic acid ( cis-9, trans-11-octadecadienoic acid) labeled with deuterium atoms on the 17- and 18-carbon atoms (17,17,18,18-d 4). The methyl cis/ trans-9, trans-11-octadecadienoate-17,17,18,18-d 4 isomer pair were obtained from the Wittig coupling of trans-2-nonenyltriphenyl-phosphonium bromide (8,8,9,9-d 4) and methyl 9-oxononanoate. To prepare the phosphonium bromide, 5-hexyn-1-ol was reduced with deuterium gas/Wilkinson's catalyst to yield 1-hexanol-5,5,6,6-d 4. The alcohol was converted to the iodide with phosphorous pentoxide/phosphoric acid/potassium iodide. Coupling of the iodide with 2-propyn-1-ol via lithium amide in liquid ammonia gave 2-nonyn-1-ol-d 4. The acetylenic alcohol was reduced with lithium metal in liquid ammonia to yield the trans-2-nonen-1-ol-d 4. The alcohol was converted to the bromide (using triphenylphosphine dibromide) and then converted to the phosphonium salt. The aldehyde ester was prepared by the reductive ozonization of methyl 9- cis-octadecenoate. The two conjugated linoleic acid isomers, formed during the final Wittig coupling reaction, were readily separated by a combination of reversed-phase and silver resin chromatography. Isotopic and chemical purities were >95% for each geometric isomer. Overall yield (both isomers) from the 8-step synthesis was 12%.

Regioselective Coupling Reaction of Allylic Barium Reagents with Epoxides

Abstract The regioselective coupling reaction of epoxides with allylic barium reagents was achieved. All reactions resulted in high yields with remarkable α-selectivities. 2-Propynylbarium reagent afforded exclusively the corresponding acetylenic alcohol.

ChemInform Abstract: Influences of the Heteroatom on the Reactivity of Silicon‐ and Germanium‐Containing Acetylenic Alcohols, Ethers, and Carbonyl Compounds

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Zeolite-catalyzed oxidation of benzylic and acetylenic alcohols with t-butyl hydroperoxide

4 A molecular sieves catalyze the mild conversion of activated secondary alcohols into the corresponding carbonyl compounds with t-butyl hydroperoxide (TBHP).

Chemoenzymatic synthesis of (+)-(4E,15E)-docosa-4,15-dien-1-yn-3-ol, a component of the marine sponge Cribrochalina vasculum

An acetylenic alcohol, (+)-(4E, 15E)-docosa-4,15-dien-1-yn-3-ol 1, isolated from the marine sponge Cribrochalina vasculum, was synthesized in highly enantiomerically pure form by lipase-catalysed transesterification with Novozym 435 (Candida antarctica).