用Sharpless不对称双羟化反应合成手性β-氨基醇

以烯烃为原料合成了一组对映体纯的β-氨基醇．在手性配体1,4-双(9-O-奎宁)-2,3-二氮杂萘[(QN)₂PHAL]存在下, 通过烯烃的Sharpless不对称双羟化、环化、亲核开环和催化氢化等步骤方便地合成了手性β-氨基醇. 从环氧化物到氨基醇的总产率为89%～94%, β-叠氮醇和β-氨基醇的光学纯度高达90%～99% ee. 同时考察了影响环氧化物开环的各种因素．     

Production of Mixed Alcohols from Bio-syngas over Mo-based Catalyst

A series of Mo-based catalysts prepared by sol-gel method using citric acid as complexant were successfully applied in the high effcient production of mixed alcohols from bio-syngas, derived from the biomass gasification. The Cu₁Co₁Fe₁Mo₁Zn_0.5-6%K catalyst exhibited a higher activity on the space-time yield of mixed alcohols, compared with the other Mo-based catalysts. The carbon conversion significantly increases with rising temperature below 340 oC, but the alcohol selectivity has an opposite trend. The maximum mixed alcohols yield derived from biomass gasification is 494.8 g/(kg_catal·h) with the C2⁺ (C2-C6 higher alcohols) alcohols of 80.4% under the tested conditions. The alcohol distributions are con-sistent with the Schulz-Flory plots, except methanol. In the alcohols products, the C2⁺ alcohols (higher alcohols) dominate with a weight ratio of 70%-85%. The Mo-based cata-lysts have been characterized by X-ray diffraction and N2 adsorption/desorption. The clean bio-fules of mixed alcohols derived from bio-syngas with higher octane values could be used as transportation fuels or petrol additives.     

Polymers containing fluorinated ketone groups. II. NMR studies of the reaction of methylbenzyl trifluoromethyl ketones with alcohols in carbon tetrachloride

Prior to the study of poly(o- and p-vinylbenzyl trifluoromethyl ketone) (PVTFK) polymers and their reaction with alcohols, the reactions of some simple model compounds with alcohols were investigated. The reaction of fluorinated ketones toward alcohols was determined by proton nuclear magnetic resonance (NMR) spectroscopy. Two fluorinated ketones–p-methylbenzyl trifluoromethyl ketone (p-MTFK) and o-methylbenzyl trifluoromethyl ketone (o-MTFK)–were prepared. Studies of the reaction of p-MTFK and o-MTFK to various alcohols based on NMR produced equilibrium constants (1M in CCl₄) at 31°C that ranged from 0.1 to 6.0. The equilibrium constants for p-MTFK with alcohols were larger than those for o-MTFK. In addition, the equilibrium constants for primary alcohols were larger than those for secondary and tertiary alcohols. Steric effects in this reaction could explain the lowered equilibrium constants for o-MTFK and the secondary and tertiary alcohols.     

Investigations of vinyl ethers of the furan series

A number of 5-aminomethylfurfuryl alcohols were synthesized by the Mannich reaction from furfuryl alcohol, secondary amines, and paraformaldehyde. The corresponding vinyl ethers were obtained by reaction of these alcohols with acetylene. The PMR spectra of the vinyl ethers of 5-piperidino- and 5-diallylaminomethylfurfuryl alcohols are described.For Communication V, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1299–1302, October, 1970.     

Separation of a Homologous Series of Long-Chain Fatty Alcohols (C49-C58) From Mycobacterium Tuberculosis H37Ra by High Performance Liquid Chromatography

Abstract

Fatty alcohols were obtained from the saponified chloro-form-methanol extract of Mycobacterium tuberculosis H37Ra by extraction with diethyl ether and partially purified by silicic acid column chromatography. The long-chain fatty alcohols (C₄₉-C₅₈) were separated from the shorter-chain alcohols by Sephadex LH-20 column chromatography and further fractionated into saturated and unsaturated alcohols by argentation thin-layer chromatography. These two fractions were analyzed by proton nuclear magnetic resonance spectro-scopy, derivatized to the 3,5-dinitrobenzoyl esters, and fractionated on a C₁₈-bonded silica column by high performance liquid chromatography (HPLC). Complete separation of esters differing by two carbon units and partial separation     

Mechanochemically Initiated Achmatowicz Rearrangement

The Achmatowicz rearrangement converts furfuryl alcohols, obtainable from renewable carbohydrates, into 6-hydroxy-2H-pyrane-3(6H)-ones, which are versatile intermediates for organic synthesis. We describe here the first examples of a solvent-free mechanochemical Achmatowicz rearrangement. Furfuryl alcohols were prepared from furfurals using mechanochemically initiated reductions and Reformatsky reactions. Mechanochemical reaction conditions for the Achmatowicz rearrangement of the obtained furfuryl alcohols were optimized and applied to a series of derivatives, yielding the corresponding rearrangement products in yields of 39 to 95%.     

Quantitative Bestimmung primärer aliphatischer Alkohole (C6-C10) mit Hilfe einer pyridinnukleotidunabhängigen Alkoholdehydrogenase ausPseudomonas putida

A new enzymatic method for microdetermination of longer chain alcohols has been established withNAD(P)-independent alcohol dehydrogenase from an alkane-oxidizing strain ofPseudomonas putida. The alcohols were estimated spectrophotometrically by measuring the formazan formation from the corresponding tetrazolium salt. Amounts of longer chain alcohols up to 3 nmol could be assayed by reading the endpoint of the reaction, even in presence of a 1000-fold exess of ethanol.     

Synthesis of 1,2- and 1,4-amino alcohols from 1,3-dienes via oxazines. Rearrangements of 1,4-amino alcohol derivatives to oxazolines

Conjugated dienes were converted to 1,2-oxazines by reaction with an acyl nitroso dienophile. The oxazines were reduced to 1,4-N-acetylamino alcohols, which were rearranged to the corresponding oxazolines upon treatment with methanesulfonyl chloride or anhydride. The oxazolines yielded 1,2-N-acetylamino alcohols upon hydrolysis. Thus either 1,4- or 1,2-N-acetylamino alcohols are available from 1,3-dienes via this methodology. Experimental and spectral data are provided for all new compounds.     

A short synthesis of α-allenic alcohols from α,β-unsaturated carbonyl compounds with dichloromethyl p-tolyl sulfoxide

The reaction of the α-sulfinyl carbanion of dichloromethyl p-tolyl sulfoxide with α,β-unsaturated carbonyl compounds gave 1-chlorocyclopropyl p-tolyl sulfoxides having a carbonyl group in good to high yields. The carbonyl groups in the products were reduced or treated with alkylmetals to give alcohols. Finally, the alcohols were treated with Grignard reagent to give α-allenic alcohols via the rearrangement of the cyclopropylmagnesium carbenoid intermediates, which were generated by the sulfoxide-magnesium exchange reaction, in good to high yields. This procedure provides a new method for a short synthesis of various α-allenic alcohols in two or three steps from relatively easily available α,β-unsaturated carbonyl compounds.     

Heterocyclic Spiro-naphthalenones. Part II. Synthesis and reactions of some spiro [tetrahydrofuran-2,1′-(2′H-naphthalene)]-2′,5-diones and Spiro [tetrahydrofuran-2,2′-(1′H-naphthalene)]-1′,5-diones

The spiro-lactone 3 was obtained by N-bromosuccinimide (NBS) oxidation of the carboxylate 2 at ? 20°. When 2 was oxidized at 10° the spiro-lactone 4 was the main product. Compound 4 was rearranged with triethylamine to the spiro-lactone 9 whereas the stereoisomeric spiro-lactones 14 and 15 were obtained by NBS oxidation of the carboxylate 13 . The ketones 3, 4, 9, 14 and 15 were reduced with NaBH₄ to the corresponding alcohols 5, 6, 10, 16 and 18 respectively; these were hydrogenated to the alcohols 7, 8, 11 and 20 . The allylic alcohols 5 and 6 gave the benzochromanone 1 when heated in polyphosphoric acid whereas the benzochromanones 12 and 21 were obtained from the alcohols 10 and 16 respectively.     

Group contributions to the infinite dilution partial molar volumes of alkanes, alcohols, and glycols in polar organic solvents

Densities of binary mixtures of polar organic solvents with alcohols were measured at 25‡C. The solvents studied were N,N-dimethylformamide, dimethylsulfoxide, and formamide while alcohols were butanol, pentanol, hexanol, and 1,4-butanediol. Density measurements of hydrocarbons (from pentane to dodecane and some heptane isomers) + N,N-dimethylformamide were also performed. From these data the apparent molar volumes of alcohols and hydrocarbons as functions of concentration were calculated. The standard partial molar volumes were obtained by extrapolation to infinite dilution and are discussed in terms of group contributions.     

Fluorescent cyclodextrins as chemosensors for the detection of cyclic and acyclic alcohols

Molecular sensing abilities and selectivities of a “turn-on” chemosensor, NBDamine-appended α-cyclodextrin (NC0αCD), were studied for cyclic alcohols and acyclic alcohols. This chemosensor is more sensitive to cyclic alcohols than acyclic alcohols, although its binding affinity is stronger for acyclic alcohols than cyclic alcohols.     

Regio- and stereoselective synthesis of (Z)-2-Arylsulfanyl allylic alcohols using anhydrous CeCl3 as catalyst under solvent free conditions

Anhydrous CeCl₃ was successfully employed as catalyst for the synthesis of (Z)-2-Arylsulfanyl allylic alcohols from propargylic alcohols and thiols under solvent free conditions. The products were obtained in good to excellent yields.     

Imidazolinium sulfonate and sulfamate zwitterions as chiral solvating agents for enantiomeric excess calculations

The synthesis of enantiopure unsymmetrical N-heterocyclic based zwitterions incorporating imidazolinium and alkylsulfonate or sulfamate groups is described. The desired compounds were prepared in good yields from 1,3-propanesultone or cyclic sulfamidates and imidazolines. The imidazolinium based zwitterions proved to be versatile chiral solvating agents for Mosher’s acid, alcohols, cyanohydrins, amino alcohols, nitro alcohols, thiols, and carboxylic acids with very high shifts in the ¹H and ¹⁹F NMR.     

Synthesis and biological evaluation of (S)-4-aminoquinazoline alcohols

A simple synthetic method for the preparation of enantiomerically pure (S)-4-aminoquinazoline alcohols from (S)-quinazolinone alcohols by key steps including chlorination, nucleophilic ipso substitution, and deacetylation is presented. Mutagenic and antimutagenic properties of the (S)-4-aminoquinazoline alcohols were investigated by using Salmonella typhimurium TA1535, and Escherichia coli WP2uvrA tester strains at 0.01, 0.1, and 1 μg/plate concentrations. (S)-4-aminoquinazoline alcohols were found to be genotoxically safe at the tested concentrations. Among the tested (S)-4-aminoquinazoline alcohols, the best antimutagenic activity was obtained with a methyl derivative at 0.1 μg/plate dose.     

Distribution coefficients in the water-dodecane system and the heats of adsorption of C<Subscript>1</Subscript>-C<Subscript>8</Subscript> alcohols on silica

Distribution coefficients in the water-dodecane system and the heats of adsorption of C₁-C₈ alcohols on silica (Silochrom S-80) were determined by gas chromatography. At low temperatures, C₁-C₄ alcohols were largely distributed in the aqueous phase, and C₆-C₉ alcohols were predominantly dissolved in the organic phase; C₅ alcohols had intermediate properties. Permittivity was found to correlate with log K _d, which allowed us to predict the character of the distribution of alcohols in the water-oil system. The heats and isotherms of adsorption were determined for the alcohols studied. The heats of adsorption of alcohols on silica monotonically increased in the series under consideration. For C₅-C₈ alcohols, they exceeded the heat of adsorption of water. The isotherms of adsorption were described by the Freundlich equation.     

Probing the specificity of the S1′, leaving group,site of subtilisin Bacillus lentus using an enzyme-catalyzed transesterification reaction

Subtilisin Bacillus lentus catalyzes transesterifications between N-acetyl-L-phenylalanine vinyl ester and a wide range of alcohols. Reaction yields are high when primary alcohols are used, and quantitative with methanol. With chiral alcohols, the reaction is enantioselective, and the stereoselectivity is reversed on going from open chain secondary alcohols to β-branched primary alcohols. A model is proposed to account for this change in absolute configuration preference.     

Functionalized Resins for the Synthesis of Peptide Alcohols

Peptide alcohols are clinically important compounds that are underexplored in structure–activity relationship (SAR) studies in drug discovery. One reason for this underutilization is that current syntheses are laborious and time consuming. Herein, we describe the preparation and utility of Rink, Ramage, and Sieber-chloride resins, which enables the use of a general, easy and practical method for the attachment of fluorenylmethoxycarbonyl (Fmoc)-amino alcohols to a solid support, in the synthesis of peptide alcohols. This method is the first straightforward Fmoc/tBu synthesis of peptide alcohols starting from a pre-loaded resin. The synthesized peptide alcohols can be detached from the linkers through conventional methods. Treatment with trifluoroacetic acid (TFA) (95 %) and scavengers such as triisopropylsilane and water for 2 h is sufficient to obtain a fully deprotected peptide alcohol, while treatment with 20 % hexafluoroisopropanol in dichloromethane renders a fully protected peptide alcohol that can be further modified at the C-terminus. As examples, the new resins were used in straightforward, relatively rapid syntheses of the peptide alcohols octreotide, alamethicin, and a segment of trichogin GA IV, as well as the first synthesis of stapled peptide alcohols.     

Stereochemistry of ethynylation of 2,7-dialkyl- and 1,2,7-trialkyl-trans-decahydro-4-quinolones

The effect of the nature of the acetylide, the temperature, and the character of the solvent on the stereochemistry of ethynylation of isomeric 2,7-dialkyl- and 1,2,7-trialkyldecahydro-4-quinolones was investigated. Acetylenic alcohols that have an axially oriented ethynyl grouping were synthesized. Conditions for the stereospecific synthesis of epimeric (with respect to C₄) acetylenlc alcohols were found. The isomers of acetylenic alcohols obtained were incapable of interconversions under the reaction conditions.See [1] for our preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1091, August, 1980.     

Higher alcohol synthesis over Cu-Fe composite oxides with high selectivity to C2+OH

Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C₂₊OH and C₆₊OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity (GHSV) on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon.