Consecutive Reactions of Dialkyl Ethynyl Carbinols with Acetylene in Superbase KOH/DMSO Suspension

2-Methylbut-3-yn-2-ol, a tertiary propargylic alcohol, reacts with acetylene under pressure in superbase KOH/DMSO suspension (80 °C, 1 h) to afford, along with the expected vinyl ether, 2,2,4,4-tetramethyl-5-methylidene-1,3-dioxolane, 2,5-dimethyl-5-(vinyloxy)hex-3-yn-2-ol and (Z)-2-methyl-4-(2-methylbut-3-yn-2-yloxy)but-3-en-2-ol.     

Isolation,Structure Determination and Synthesis of New Acetylenic Steroids from the Sponge Calyx nicaaensis

Two acetylenic steroids, cholest-5-en-23-yn-3β-ol ( 5 ) and 26,27-dinorcholest-5-en-23-yn-3β-ol ( 3 ), and another unsaturated steroidalcohol, stigmasta-5,23-dien-3β-ol ( 7 ), were isolated from the sponge Calyx nicaaensis. The structures of these two acetylenic steroids were established by synthesis. Several attempts to synthesize the marine steroids alcohol calysterol ( 1 ), with a cyclopropene-containing side chain, starting from cholest-5-en-23-yn-3β-ol are also recorded. Addition of ethyl-diazo-acetate to the triple bond was performed, but the reduction to the methyl derivative yielded decomposition products.     

Synthetic study of hepoxilins

Total synthesis of trioxilin (10S,11S,12S)-B₃ was performed starting from a hepoxilin synthon, (2S,3S)-2,3-epoxyundec-5-yn-1-ol, available from the corresponding allylic alcohol by Sharpless enantiodirected epoxidation. The synthesis features stereoselective (7 ∶ 1)syn-addition of the acetylenide anion to the intermediate (2S,3S)-2,3-(isopropylidenedioxy)undec-5-yn-1-al and regioselective partial hydrogenation of a triacetylene trioxilin precursor, which allowed the preparation of 14,15-dehydro-(10S,11S,12S)-TrXB₃. For part 8, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 545–551, March, 2000.     

Coupling reactions of aryl bromides with 1-alkynols catalysed by a tetraphosphine/palladium catalyst

cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C₃H₅)]₂ system catalyses efficiently the coupling reactions of aryl halides with a variety of alkynols such as propargyl alcohol, but-1-yn-4-ol, pent-1-yn-5-ol or hex-1-yn-6-ol. The catalyst can be used at low loading. Higher reaction rates were observed in the presence of but-1-yn-4-ol, pent-1-yn-5-ol or hex-1-yn-6-ol than with propargyl alcohol. The protection of the alcohol functions as an ether or a silyloxy group led generally to similar or better results than the reactions performed with the unprotected alcohols.     

1,3-dipolar cycloaddition reactions in the series of <Emphasis Type="Italic">N</Emphasis>-alkynyl-substituted uracils

Reactions of 1-(ω-bromoalkyl)-3,6-dimethyluracils and 1,3-bis(ω-bromoalkyl)-6-methyluracils with sodium azide gave the corresponding mono- and bis-azides. 1,3-Dipolar cycloaddition of the latter with prop-2-yn-1-ol, hex-1-yne, and dec-1-yne in the presence of copper(I) ions afforded acyclic and macrocyclic uracil derivatives containing 1,4-disubstituted 1,2,3-triazole fragments, which were subjected to quaternization with propyl iodide and methyl p-toluenesulfonate at the 1,2,3-triazole nitrogen atom.     

Lipase-mediated deracemization of secondary 1-phenyl-substituted propargylic alcohols of different topology

Acetylation of (±)-1-phenylnon-2-yn-1-ol, (±)-1-phenylhept-1-yn-3-ol, and (±)-1-phenylundec-4-yn-3-ol ((±)-5) in the presence of lipase from Candida cylindracea (CCL) proceeds slowly to give products with ee 20%. The acetates of these alcohols are hydrolyzed in the presence of porcine pancreatic lipase (PPL) equally unsatisfactorily. The (⁶-arene)tricarbonylchromium complex of alcohol (±)-5 is acetylated in the presence of CCL up to 22% conversion to give (R)-acetate whose oxidative decomplexation followed by saponification results in alcohol (R)-(–)-5 with ee 95%. The configuration of alcohols (–)-5 and (+)-5 was determined by NMR spectroscopy of their esters with (R)- and (S)-Mosher"s acids.     

Ruthenium- and palladium-catalyzed synthesis of polyfunctional 1,3-dienes

The ruthenium-catalyzed Markovnikov addition of acetic or benzoic acid to the triple bond of (E)-3-methylpent-2-en-4-yn-1-ol followed by acylation of the alcohol group in the diene formed under the action of low-toxic derivatives of carbonic and formic acids opens up a simple route to dienylic carbonates and formates. Activation of these esters by catalytic amounts of palladium(0) complexes under conditions of nucleophilic allylic substitution or decarboxylation affords functional dienes. Laboratoire de Chimie de Coordination et Catalyse, UMR 6509: CNRS—Unversité de Rennes, Campus de Beaulieu, 35042 Rennes, France. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 943–946, May, 1998.     

5-Hydroxy substituted naphthofurans and naphthothiazoles as precursors of photochromic benzochromenes

3-Benzoylnaphtho[1,2-b]furan-5-ol forms a photochromic benzochromene upon reaction with a 1,1-diarylprop-2-yn-1-ol affording a red coloured photomerocyanine, with a half-life of 2.3 min, upon UV-irradiation. Retention of the initial 1,4-oxygenation pattern of the naphthalene moiety through replacement of the furan unit with a methoxy group led to a benzochromene, which developed a similar red colour upon UV-irradiation but was more persistent with a half-life of over 42 min. Treatment of the 3-benzoylnaphtho[1,2-b]furan-5-ol with a 1,1,3-triarylprop-2-yn-1-ol similarly afforded a benzochromene, which did not display any photochromism at ambient temperature as a consequence of steric interactions in the photomerocyanines. The synthesis of N-(5-hydroxynaphtho[1,2-d]thiazol-2-yl)acetamide, as a precursor to a photochromic hetero-fused benzochromene, by the mild selective deprotection of the O-acetyl group of 2-acetamidonaphtho[1,2-d]thiazol-5-yl acetate was complicated by a facile, competitive, oxidative dimerisation to afford a novel [2,2′-binaphthothiazole]-1,1′-diol.     

Synthesis of Abscisic Acid

A stereoselective synthesis of (±)-abscisic acid ( 7 ) is described in which 2-cis 3-methylpent-2-en-4-yn-1-ol ( 2 ) is used to introduce the 2-cis, 4-trans geometry.     

A Stereoselective Synthesis of Ethyl (2E,4Z)-2,4-Decadienoate: Pear Ester

A stereoselective synthesis of ethyl (2E, 4Z)-2,4-deca-dienoate (1) is reported from E-pent-2en-4-yn-1-ol in five steps.     

Novel Synthesis of 3,5,5-Trimethyl-4-(2-butenylidene)-cyclohex-2-en-1-one,a Major Constituent of Burley Tobacco Flavour

The acetylenic diol 2 , prepared by reaction of but-3-yn-2-ol dianion with 2,6,6-trimethyl-4,4-ethylenedioxy-cyclohex-2-en-1-one ( 1 ), afforded 3,5,5-trimethyl-4-(2-butenylidene)-cyclohex-2-en-1-one ( 4 ), a major constituent of Burley tobacco flavour, upon LiAlH₄ reduction and hydrolysis. Vomifoliol ( 5 ) and blumenol C ( 6 ) were major by-products in this reaction.     

Development of a method for the preparation of ruthenium indenylidene-ether olefin metathesis catalysts

The reactions between several derivatives of 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and different ruthenium starting materials [i.e., RuCl?(PPh?)? and RuCl?(p-cymene)(L), where L is tricyclohexylphosphine di-t-butylmethylphosphine, dicyclohexylphenylphosphine, triisobutylphosphine, triisopropylphosphine, or tri-n-propylphosphine] are described. Several of these reactions allow for the easy, in-situ and atom-economic preparation of olefin metathesis catalysts. Organic precursor 1-(3,5-dimethoxyphenyl)-1-phenyl-prop-2-yn-1-ol led to the formation of active ruthenium indenylidene-ether complexes, while 1-(3,5-dimethoxyphenyl)-prop-2-yn-1-ol and 1-(3,5-dimethoxyphenyl)-1-methyl-prop-2-yn-1-ol did not. It was also found that a bulky and strong σ-donor phosphine ligand was required to impart good catalytic activity to the new ruthenium complexes.     

Synthesis of esters of stereoisomeric 4,5-dimethylhepta-2,4-dien-6-ynoic acids

Summary We determined the ratio of the geometric isomers of 2,3-dimethyl-2-penten-4-yn-1-al, formed in the oxidation of 2,3-dimethyl-2-penten-4-yn-1-ol and of the corresponding bromide, and we also synthesized some esters of the isomeric 3,4-dimethylhepta-2,4-dien-6-ynoic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 546–548, March, 1965     

A versatile approach to the synthesis of 9(Z)-unsaturated acyclic insect pheromones from undec-10-enoic acid

A general approach to the synthesis of 9(Z)-unsaturated acyclic insect pheromones from undec-10-enoic acid was developed. The method comprises the conversion of the acid into undec-10-enyl acetate, shortening of its carbon chain to afford dec-9-enyl acetate (via 11-acetoxyundecanoic acid), and a two-step transformation of the latter into the key intermediate, dec-9-yn-1-ol, by sequential bromination—dehydrobromination. The elimination of two HBr molecules from the dibromide is effectively performed using Bu¹OK in the presence of dibenzo-18-crown-6 as the catalyst. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1637–1639, August, 1998.     

Hypohalogenation of vinyl- and allylacetylenes and some chemical transformations of the products

Hypohalogenation of 2-methylhex-5-en-3-yn-2-ol, 2-methylhept-6-en-3-yn-2-ol, and their methyl ethers at 303–328 K with hydrochloric or hydrobromic acid in the presence of hydrogen peroxide involves only the double bond to produce the corresponding halohydrins in fairly high yields. Kinetic parameters of these reactions were determined, and the allylacetylenic alcohol and its methyl ether were found to be more reactive than their vinylacetylenic analogs. Acetylenic halohydrins and oxiranes derived therefrom were shown to be quite reactive compounds which may be used as building blocks in organic synthesis.     

Synthesis and photoluminescence properties of 8-hydroxyquinoline derivatives and their metallic complexes

Three new 8-hydroxyquinoline derivatives, i.e. 5-[(4-styryl-benzylidene)-amino]-quinolin-8-ol (1), 5-[(4-bromo-2-fluoro-benzylidene)-amino]-quinoline-8-ol (2) and 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol (3), and their metallic complexes were synthesized and identified by ultraviolet-visible (UV-Vis), ¹H nuclear magnetic resonance (¹H NMR), Fourier transform infrared spectrometer (FTIR), mass spectrometry (MS) spectra and elemental analyses. Their fluorescence properties were studied by photoluminescence, which indicated that the luminescence wavelength of 5-and 2-substitued-8-hydroxyquinoline derivatives shifted to red in comparison with that of 8-hydroxyquinoline. Meanwhile, the fluorescence lifetime of 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol and its zinc complex showed long lifetime in benzene solution. __________ Translated from Chinese Journal of Organic Chemistry, 2007, 27(3): 402–408 [译自: 有机化学]     

Essential oils of mongolian plants

1. The following compounds have been isolated by gas-liquid chromatography from the essential oil ofArtemisia rutifolia Steph. ex Spreng. growing in the Mongolian People's Republic and have been identified by their IR spectra: 1,8-cineole (35%), α-thujone andβ-thujone (11%), (+)-camphor (18%), (−)-α-terpineol (5%), and (−)-terpinen-4-ol (7%). By analytical gas chromatography α-pinene,β-pinene, camphene, limonene,β-phellandrene, and p-cymene have been identified in the hydrocarbon fraction. It has been shown that apart from compounds of a terpene nature the oil contains 4-phenylbutan-2-one, (±)-4-phenyl-butan-2-ol, and (±)-4-phenylbut-2-yl acetate. This is the first time that (±)-4-phenylbutan-2-ol and its acetate has been found in plant material.     

Chiral imines and amines based on 2-hydroxypinan-3-one

The new chiral derivatives of benzylamine and 2α-hydroxypinan-3-one (1R,2R,5R)-3-[(1S)-α-methylbenzylamino]-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol (2), (1S,2S,3S,5S)-3-(benzylamino)-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol (3), and (1R,2R,3R,5R)-3-[(1S)-α-methylbenzylamino]-2,6,6-trimethylbicyclo[3.1.1]heptan-2-ol (4) were synthesized and characterized. It was shown that reduction of the benzylimines by sodium triacetoxyborohydride formed stereoselectively 3β-substituted pinanamines.     

Reactivity of primary and secondary alcohols in nucleophilic addition to a triple bond: the vinylation of butane-1,3-diol

Acetylene adds to butane-1,3-diol in the presence of KOH to give, along with the corresponding divinyl ether and 2,4-dimethyl-1,3-dioxane, 4-vinyloxybutan-2-ol and its structural isomer 3-vinyloxybutan-1-ol, the ratio between the latter two products, (5–8)∶1, depending on the reaction conditions. Translated fromIzvestiya Akademii Nauk, Seryia Khimicheskaya, No. 12, pp. 2372–2374, December, 1999.     

Effect of solvent on the kinetics of arylsulfonylation of N-alkylated anilines in a water-propan-2-ol system

The effect of the composition of a water-propan-2-ol solvent on the kinetics of arylsulfonylation of N-ethyl-, N-isopropyl-, and N-butylanilines with 3-nitrobenzenesulfonyl chloride at 298 K was studied. The reaction rate constant increases monotonically with an increase in the water fraction in the solvent from 5 to 30 wt.%. The apparent activation parameters of the reaction of N-butylaniline with 3-nitrobenzenesulfonyl chloride were calculated. No considerable changes in the activation parameters of the reaction were observed on going from pure propan-2-ol to a 10% aqueous solution, which indicates that the mechanism remains unchanged upon solvent change. Propan-2-ol with a water content of 5–30 wt.% can be used in the synthesis of arylsulfonylation products of the amines under study in 98–99% yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 937–939, June, 2006.