A convenient preparative method for 2,4-dialkyl-2-cycloalkenyl-γ-butyrolactones

Several, 2,4-dialkyl-2-cycloalkenyl-γ-butyrolactones were synthesised from 2-(cycloalken-1′-yl) carboxylic acids and epoxides using lithium naphthalenide in the presence of diethylamine. From 2-(cyclohexen-1′-yl)propanoic acid and propylene oxide, 4-hydroxy-2-(cyclohexen-1′-yl)-2-methylpentanoic acid was obtained. The latter easily cyclised to give 2-(cyclohexen-1′-yl)-2,4-dimethyl-γ-butyrolactone. Similarly, 2,4-dialkyl-2-(cycloalken-1′-yl)-μ-butyrolactones were prepared from other 3,4-unsaturated carboxylic acids and epoxides. These lactones may be used as perfumery materials.     

Products from the reaction of fatty acids with ketones and their characteristic properties as cutting fluids additives

Hydroxy acids were synthesized in good yields from ketones and fatty acids by the use of lithium naphthalene in the presence of diethylamine. For example, from cyclohexanone and undecylenic acid (I), 2-(1-hydroxy-1-cyclohexyl)-10-undecenoic acid (III) was obtained in 92% yield. Hydroxy acids were treated withp-toluenesulphonic acid to give corresponding unsaturated fatty acids. From the reaction of (III), 2-(1-cyclohexenyl)-10-undecenoic acid (IV), a 3,4-unsaturated acid was obtained (yield 59%). Corrosion and lubricity tests for these products as water-based cutting fluid additives were carried out. We have found that triethanolamine salts of 2-cyclohexenyl and 2-hydroxycyclohexyl fatty acids showed effective rust-inhibiting and antiwear properties for water-based cutting fluids.     

A reaction of 3,4-unsaturated carboxylic acids with paraformaldehyde or 1,3,5-trioxane

3,4-Unsaturated acids were condensed with paraformaldehyde in boiling acetic acid containing a small amount of aluminium chloride to afford 2,3-unsaturated-δ-lactones. For example, from 2-(cyclohexen-1′-yl)caprylic acid (I) and paraformaldehyde, 2′-hydroxymethyl-2-cyclohexylidenecaprylic acid lactone (II) was obtained in up to 93% yield. Several 2,3-unsaturated-δ-valerolactones were obtained in good yield by this new method. These lactones may be used as perfumery materials.     

A convenient one step synthesis of 2,4-dialkyl-2-hydroxy-alkyl-γ-butyrolactone using lithium naphthalenide

One mole of propionic acid ( I ) reacts with 2 mol of 1,2-butylene oxide ( II ) in the presence of lithium naphthalenide to give 4-hydroxy-2-(2′-hydroxybutyl)-2-methylhexanoic acid ( V ), which can be easily converted into 2-(2′-hydroxybutyl)-2-methyl-4-ethyl-γ-butyrolactone ( VII ). Similarly, 2,4-dialkyl- and 2,4,4-trialkyl-2-hydroxyalkyl-γ-butyrolactones were prepared from other carboxylic acids having two hydrogens at 2-position and various epoxides.     

A convenient preparative method for mintlactone and isomintlactone

Various 2-(2′-hydroxy-4′-methyl-1′-cyclohexylidene) carboxylic acid lactones were synthesised in good yield from carboxylic acids and 4-methylcyclohexanone. For example, mintlactone ( VI ) and isomintlactone ( VII ) were prepared from 2-(1′- hydroxy-4′-methylcyclohexan-1′-yl) propanoic acid ( III ) which was obtained by reaction of propanoic acid ( I ) with 4-methylcyclohexanone ( II ) using lithium naphthalenide in the presence of diethylamine. Compound ( VI ) could be separated from compound ( VII ) by silica gel column chromatography. Several new 2-(2′- hydroxy-4′-methyl-1′-cyclohexylidene) carboxylic acid lactones which may be used as perfumery materials, were obtained in good yield by this method.     

Enantioselective hydrogenation of fluorinated unsaturated carboxylic acids over cinchona alkaloid modified palladium catalysts

The hydrogenation of trifluoromethyl substituted prochiral α,β-unsaturated carboxylic acids has been studied over cinchona alkaloid modified palladium heterogeneous catalysts. Low enantioselectivities were obtained in the hydrogenation of all three test compounds, 2-trifluoromethylacrylic acid, 4,4,4-trifluoro-3-methyl-2-butenoic acid and (E)-4,4,4-trifluoro-3-phenyl-2-butenoic acid, respectively. Significant increase in the enantioselectivity, up to 43%, was obtained in the hydrogenation of 4,4,4-trifluoro-3-methyl-2-butenoic acid by using benzylamine as additive. The presented results showed for the first time the possibility of enantioselective hydrogenation of α-unsubstituted β-disubstituted α,β-unsaturated carboxylic acids in the cinchonidine modified palladium catalytic system, that resulted in optically enriched saturated acids having the chiral center in β position.     

Convenient preparative method for lactones from 3-hydroxy propanoic acids using iodine under solvent-free conditions

Intramolecular cyclization of 3-hydroxy acids was investigated using iodine as a catalyst under solvent-free conditions. The reaction proceeded to completion in the heterogeneous system. Lactones were obtained by intramolecular cyclization of 3-hydroxy acids. Propella lactone (11-oxatricyclo[4.4.3.0(1,6)]tridecan-12-one) was conveniently synthesized from 3-hydroxy acid ((6-hydroxyspiro[4.5]dec-6-yl)acetic acid) in 88% yield with carbon skeleton rearrangement. Spiro lactones and bicyclic lactones were also obtained from the corresponding 3-hydroxy acids in yields of over 75%. The most suitable reaction conditions were a temperature of 80 degrees C, a molar ratio of 3-hydroxy acid:iodine = 1:0.1, and a time period of 6 h. In addition, terpenic lactones were efficiently synthesized from the corresponding 3-hydroxy acids, derived from (+)-camphor, (-)-fencone, and (-)-pulegone, with skeleton rearrangement. The yield of the solvent-free reaction was as high as that of the corresponding reaction in solution.     

A convenient preparative method for carboxylic acids containing the dichlorocyclopropane ring system

Various carboxylic acids containing the dichlorocyclopropane ring system were prepared from the direct reaction of unsaturated carboxylic acids with dichlorocarbene. For example, 2-(2,2.dichloro-1-methylcyclopropyl)-ethanoic acid ( II ) was prepared from 3-methyl-3-butenoic acid ( I ), 50% aqueous sodium hydroxide solution and benzyltriethylammonium chloride (BTEAC) in 80% yield. Similarly, 3-(2,2-dichloro-3,3-dimethyIcyclopropyl)-2,2-diethyl propanoic acid ( IV ) was obtained in 80% yield from 2,2-diethyl-5-methyl-4-hexenoic acid ( III ). The dichlorocyclopropane compounds, ( II ) and ( IV ), are potent insecticides against houseflies (Takatsuki strain in Japan).     

The formation of hydroxy monocarboxylic acids and dicarboxylic acids by alkaline thermochemical degradation of cellulose

Treatment of cotton cellulose with 3 M sodium hydroxide solution at 260°C and 280°C gave a mixture of carboxylic acids with a yield of > 95%. The identified 50 carboxylic acids included both hydroxy monocarboxylic acids and dicarboxylic acids; their routes of formation are discussed. Among the main compounds were lactic, glycolic, 2-hydroxy-2-methylpropanoic, 2-hydroxybutanoic, 3,4-dideoxypentonic, anhydroisosaccharinic, 2,3-dideoxypentaric, and 3,4-dideoxyhexaric acids. Technical utilisation of this kind of acid mixture requires further studies. Investigations of the cyclic compounds, formed in small amounts only, resulted in identification of mainly alkyl-substituted 2-cyclopenten-1-ones.     

A convenient preparative method of 2,3-dialkyi parasorbic acids from carboxylic acids

Various 2,3-dialkyl parasorbic acids were prepared from carboxylic acids. For example, 2-methyl-5-pentyI parasorbic acid was prepared from hexanoic acid and propanoic acid as follows: Grignard reaction of hexanoic acid ( I ) with allylmagnesium chloride gave l-nonen-4-one ( II ) and the reaction of ( II ) with propanoic acid ( III ) with lithium naphthalenide in the presence of diethylamine produced 3-allyl-3-hydroxy-2-methyloctanoic acid ( IV ). From the reaction of ( IV ) with 97% (v/v) sulphuric acid, 2-methyl-3-pentyl parasorbic acid was formed. Several 2,3-dialkyl parasorbic acids were obtained by this method. These products may be used as perfumery materials.     

Long chain carboxylic acids containing ether linkage: IV. The antibacterial activities of 0-(2-alkylaminoethyl)-3-oxypropionic and N-(2-alkyloxyethyl)-3-aminopropionic acids

The carboxylic amphoteric surfactants containing ether and substituted amine groups such as 0-(2-alkylaminoethyl)-3-oxypropionic-and N-(2-alkyloxyethyl)-3-aminopropionic acids were synthesized, and their antibacterial activities in terms of growth inhibition ofStaphylococcus aureus andEscherichia coli were examined. The structural effect, such as bonding position of ether and amino groups, and the chain length effect between undecyloxy-, dodecyloxy- and tridecyloxy radicals were examined, but no definite correlation between positional isomers and chain length and antibacterial activities was observed. Furthermore, to study the effect of the increase of the number of ether or amino groups on the antibacterial activities, N-(2-(2-dodecyloxyethyl)-aminoethyl)-3-aminopropionic acid and N-(2-(2-dodecyloxyethyl)oxyethyl)-3-aminopropionic acid were synthesized. Their antibacterial activities were almost as effective as the corresponding amino or ether acids. Moreover aqueous solution of these substituted propionic acids showed better surface activities at pH 4.0, 7.0 and 10.0.     

Synthesis of 6-hydroxy δ-lactones and 5,6-dihydroxy eicosanoic/docosanoic acids from meadowfoam fatty acids via a lipase-mediated self-epoxidation

Meadowfoam fatty acids were reacted with hydrogen peroxide in a lipase-catalyzed autocatalytic system, forming a mixture of 5,6-epoxyeicosanoic, 13,14-epoxydocosanoic, 5,6-epoxydocosanoic, and 5,6-13,14-diepoxydocosanoic acids in 98% yield. The 5,6-epoxy acids were cyclized to 6-hydroxy δ-eicosanoic/docosanoic lactones by sulfuric acid catalysis in high yield (99%). 5,6-Dihydroxy acids could be obtained from 6-hydroxy δ-lactones by a simple alkaline work-up procedure. Meadowfoam fatty acids were converted (77% yield) in a one-pot reaction to 6-hydroxy δ-lactones by in situ performic acid epoxidation and subsequent addition of sulfuric acid.     

Substituierte N,N′-Bis(thiazol-2-yl)-diaminoalkane aus α-Thiocyanato-acetophenonen und N,N′-Dialkyl-diamino-alkanen

Substituted N,N′-Bis(thiazol-2-yl)-diaminoalkanes from α-Thiocyanato-acetophenones and N,N′-Dialkyl-diaminoalkanes α-Thiocyanato-acetophenones 1 react with N,N′-dialkyl-diaminoalkanes 2 in the presence of an appropriate weak acid (acetic acid, propionic acid, benzoic acid) to give the hitherto unknown N,N′-dialkyl-N,N′-bis(4-aryl-thiazol-2-yl)-diaminoalkanes 3 . As reaction medium aliphatic alcohols (ethanol, methanol), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride) or dipolar-aprotic solvents (acetonitrile, dimethylformamide) can be used. - I.r., u.v., n.m.r. and mass spectroscopic data of the novel bisthiazoles 3 are reported.     

反-4-(5'-丙基-四氢吡喃-2'-基)-环己基甲酸的合成

以反-4-(5'-丙基-四氢吡喃-2'-基)-苯甲酸(3PyPA)为原料,经催化加氢合成顺/反-4-(5'-丙基-四氢吡喃-2'-基)-环己基甲酸(3PyHA)混合物。加氢条件实验表明,以Ru/C为催化剂,以NaOH水溶液为反应介质,当反应温度为75～85℃,压力为3.5 MPa时反应效果最佳。加氢完粗品经高温异构化反应,甲苯乙醇混合溶剂重结晶得色谱纯度99.5%以上的反-3PyHA。     

(E)-3-烷烯羧酸的合成

以脂肪醛与丙二酸为原料,通过Knoevenagel反应制备了(E)-3-烷烯羧酸,反应以二甲苯为溶剂,在回流条件下进行。考察了哌啶、吡啶及4-二甲氨基吡啶(DMAP)对反应产物的影响。结果表明,采用哌啶催化时,反应产率最高,可达70%左右,(E)-3-烷烯羧酸与副产物α,β-不饱和羧酸的摩尔比可达12/1以上;DMAP作催化剂,产率较低,在60%左右,反应选择性略高于哌啶;吡啶作催化剂时产率最低,反应选择性也最差,(E)-3-烷烯羧酸与副产物α,β-不饱和羧酸的摩尔比只有3/1。     

Kolbe-electrolysis of unsaturated carboxylic acids[1]

Reaction conditions for improved dimer yields in the Kolbe-electrolysis of β,γ-unsaturated carboxylic acids are examined. With vinylacetic acid (1) the passivation could not be lowered by decreasing neutralization, changing the anode from platinum to graphite and the solvent to methanol: pyridine, by adding p-toluenesulfonate and formate as spacers or hydroquinone as inhibitor; 1,5-hexadiene was not detectable. Shielding the double bond reduced the passivation but still yielded no dimer; shifting the double bond into γ,δ-position afforded with 2-cyclohexenylacetic acid (8) 8% dimer. When however 1 was neutralized with (C₄H₉)₃N or 8 with (C₂H₅)₃N at lower passivation 31% dimer was obtained.     

3-[(2,3-二氢噻吩并[3,4-b]-1,4-二噁英-2-基)甲氧基]-丙酸的合成工艺改进

报道了一种合成标题化合物的新工艺。以噻吩并[3,4-b]-1,4-二噁英-2-甲醇为起始原料,与丙烯酸叔丁酯发生迈克尔加成反应得到中间体化合物3-[(2,3-二氢噻吩并[3,4-b]-1,4-二噁英-2-基)甲氧基]丙酸叔丁酯。将得到的中间体在碱性条件下进行水解反应,然后采用盐酸进行酸化,最终经过干燥、减压浓缩、洗脱等后处理得到合格的标题化合物,总产率为71.2%,标题化合物及中间体经¹HNMR确认结构。路线操作简便、反应条件温和、产品质量可控,具有一定的工业应用意义。     

An efficient Synthesis of Acetylenic γ- and δ-Hydroxy Ketones, γ- and δ-keto acids,and γ- diketones via addition of 1-alkinyllithium compounds to γ- and δ-lactones

2-Hydroxy-6-alkyn-5-ones 3 , 1-hydroxy-5-alkyn-4-ones 4 , and 1-hydroxy-6-alkyn-5-ones 5 are conveniently obtained in excellent yields through a highly selective monoaddition of an 1-alkynyllithium compound 2 to γ-valerolactone (1a) , γ-butyrolactone (1b) or δ-valerolactone (1c) . They are oxidized by pyridinium dichromate or Jones reagent to the corresponding acetylenic 1,4-diketones 6 , 4-oxo carboxylic acids 7 , and 5-oxo carboxylic acids 8 , respectively.     

Synthesis and antibacterial activity of some new diarylsulphides and diarylsulphones containing azetidin-2-one and/or diazetidin-2-onyl moities

Cyclonucleophilic addition of N-phthaloylaminoacid chlorides (II on 4-(N-ary-lideneamino)-4′-nitrodiphenyl sulphides (I) in dioxane and triethylamine afforded 4-(4″-aryl-3″-phthalylamino-2″-oxo-azetidin-1″-yl)-4′-nitro-diphenyl sulphides (III). Hydrazinolysis of III yielded 4-(4″-aryl-3″-amino-2″-oxo-azetidin-1″-yl)-4′-nitro-diphenyl sulphide hydrochlorides (IV). Condensation of IV with anisaldehyde using ethanol and piperidine as a basic catalyst gave 4-(4″-aryl-3″-anisylidine amino-2″-oxoazetidin-1″-yl)-4′-nitrodiphenylsulphides (V) in good yields. Interaction of V with chloroacetyl chloride in dioxane and triethylamine produced 4-(4″-aryl-3″-substituted β-lactamyl-2″-oxo-azetidin-1″-yi)-4′-nitrodiphenyl sulphides VI. Oxidation of IV, V and VI using hydrogen peroxide/glacial acetic acid mixtures gave the corresponding sulphones (VII), (VIII) and (IX). Sulphones of the type IX were obtained by unequivocal synthesis through interaction of sulphone-anils VIII with chloroacetyl chloride. The antibacterial activities of some of these compounds were determined.     

Catalytic wet air oxidation of low molecular weight carboxylic acids using a carbon supported platinum catalyst

Aqueous solutions of low molecular weight carboxylic acids, such as acetic, propionic and butyric acids, were treated by catalytic wet air oxidation (CWAO) using a carbon supported platinum catalyst. Oxidation in the presence of the catalyst, in a stirred reactor, was carried out at 200°C and 6.9 bar of oxygen partial pressure, with conversions (after 2 h) ranging from 59.4 to 75%, and selectivities to gaseous products of up to 100%. Initial rates for conversion varied from 184 (butyric acid) to 260 mmol h⁻¹ g_Pt⁻¹ (propionic acid). The activation energy for butyric acid conversion was found to be 56.7 kJ mol⁻¹.