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4-Ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO) serves as a trifluoromethyl-containing building block for the preparation of trifluoromethyl-substituted thiophenes, furans, pyrrols, and piperazines. Key steps are an addition–elimination reaction to ETFBO followed by the thiazolium-catalyzed Stetter reaction. The scope of this chemistry was demonstrated in a new synthetic approach towards the COX-2 selective, nonsteroidal anti-inflammatory drug Celebrex® (celecoxib).

Reductions of ( Z )-C 6 H 5 CH CXC( O)CH 3 (X = Cl, Br) mediated by Saccharomyces cerevisiae , Candida albicans , Rhodotorula glutinis , Geotrichum candidum and Micrococcus luteus gave the corresponding halohydrins through consecutive reduction reactions of C C and C O bonds. In general, the reactions performed in the biphasic system water/[(bmim)PF 6 ] gave better diastereoselectivity and enantioselectivity than in pure water.

International audience; Poorly nucleophilic aromatic amines (nitroanilines, chloroanilines, etc.) react readily and selectively with trans-4-methoxy-3-buten-2-one, a convenient, effective and inexpensive surrogate for 3-butyn-2-one, to afford (Z)-enaminones. The efficiency of the reaction mostly lies in the use of water as a solvent, which enhances the reaction rate by a 45 to 200-fold factor with regard to other media.

International audience; Isoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO 2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacrolein (MACR). Unimolecular isomerization and bimolecular reactions with organic peroxy radicals are also possible. There is uncertainty about the relative importance of each of these pathways in the atmosphere and possible changes because of an-thropogenic pollution. Herein, measurements of ISOPOOH and MVK + MACR concentrations are reported over the central region of the Amazon basin during the wet season. The research site, downwind of an urban region, intercepted both background and polluted air masses during the GoAmazon2014/5 Experiment. Under background conditions , the confidence interval for the ratio of the ISOPOOH concentration to that of MVK + MACR spanned 0.4–0.6. This result implies a ratio of the reaction rate of ISOPOO with HO 2 to that with NO of approximately unity. A value of unity is significantly smaller than simulated at present by global chemical transport models for this important, nominally low-NO, forested region of Earth. Under polluted conditions, when the concentrations of reactive nitrogen compounds were high (>1 ppb), ISOPOOH concentrations dropped below the instrumental detection limit (

In the presence of InCl3 center dot 4H(2)O, the reaction of 3-bromo-4-ethoxy-1,1,1-trifluoro-3-buten-2-one 2 with a series of benzenethiols proceeds readily and gave both the addition-elimination product 3-bromo-1,1,1-trifluoro-4-thiophenyl-but-3-en-2-one and substitution product 1,1,1-trifluoro-3,4-bis-thiophenyl-but-3-en-2-one. The reactivity of benzenethiols is discussed in terms of their substituted group.

Synthetic procedures for the preparation of 1-bromo-3-butyn-2-one and 1,3-dibromo-3-buten-2-one are given. These compounds are prepared from 2-bromomethyl-2-vinyl-1,3-dioxolane, which can readily be prepared from 2-ethyl- 2-methyl-1,3-dioxolane. The synthetic routes are as follows: 2-bromomethyl-2-vinyl-1,3-dioxolane is converted to 2-(1,2-dibromoethyl)-2-bromomethyl-1,3-dioxolane. Double dehydrobromination with tBuOK affords 2-ethynyl-2-bromomethyl-1,3-dioxolane. Formolysis with formic acid gives 1-bromo-3-butyn-2-one. Deacetalized 2-bromoethyl-2-vinyl-1,3-dioxolane was treated with Br2 and Li2CO3/12-crown-4 in tetrahydrofuran to give 1,3-dibrom-3-buten-2-one in moderate yield.

1,3-Dipolar cycloaddition (1,3-DC) reaction of 4-ethoxy-1,1,1-trifluoro-3-buten-2-one 1 with nitrile oxides was studied. It was found that besides its C C participating in the formation of isoxazole rings, trifluoromethyl activated C O also underwent 1,3-DC reaction with nitrile oxides to afford 1,4,2-dioxazole rings. Single crystal diffraction analysis also evidenced the diheterocyclic configuration.

A toxicologic and dermatologic review of 4-(2,4,6-trimethyl-3-cyclohexen-1-yl)-3-buten-2-one when used as a fragrance ingredient is presented.

Two kinds of trifluoromethylated spiro or fused cyclic compounds were synthesized via the unexpected direct alpha,alpha'-dialkylation of (E)-4-ethoxy-1,1,1-trifluoro-3-buten-2-one (1) with silyl enol ethers in the presence of boron trifluoride etherate.

The reaction of (E)-4-ethoxy-l,l,l-trifluoro-3-buten-2-one EtOCH CHCOCF3 1 with diethyl phosphite (EtO)2P(O)H 2 afforded a 1:1 cis- and trans-mixture of diethyl(l-trifluomethyl-3-ethoxy)allyl-phosphate EtO–CH CH–CH(CF3)OP(O)(OEt)2 3 via the 1,2-λ5-oxaphosphol-4-ene intermediate. While tributyl phosphine Bu3P added to 1 giving the double addition product Bu3P+CH2–C−(COCF3)–CH CH–COCF3 5. Its resonance structure was fully identified by spectral methods and single crystal X-ray diffraction analysis. More strong phosphorous nucleophile tris(diethylamino) phosphine (Et2N)3P reacted with 1 to give the known compound (E)-4-(diethylamino)-l,l,l-trifluoro-3-buten-2-one Et2N–CH CH–COCF3 10 in good yield.

Dehydration of 4-hydroxy-2-butanone (HB) to 3-buten-2-one (MVK) was investigated. Anatase-TiO 2 exhibited excellent activity for the dehydration of HB with 98.8 mol% MVK yield. The highest activity was obtained at 160 °C, and deactivation was rarely observed over anatase-TiO 2 . HB decomposes into propanone above 240 °C, and the MVK selectivity decreases with increasing temperature. High acidity of catalysts causes deactivation because of strong interaction between MVK and acid sites that induces polymerization. Weak acid sites are efficient for the dehydration of HB to MVK.

The high catalytic activity and selectivity of zeolites HBeta and HZSM-12 were found in the synthesis of (E)-4-phenyl-3-buten-2-one by the reaction of styrene with acetic anhydride.

Novel heterocyclizations have been investigated based on the reaction of the complex between trifluoromethanesulfonic anhydride and 4-dimethylamino-1,1,1-trifluoro-3-buten-2-one with 2,2'-biindolyl and N,N'-dipyrrolylmethane leading to closure of 6- or 7-membered rings.

The synthesis of 1,1,1-trichloro-4,4-diethoxy-3-buten-2-one and three trichloroacetylacetate derivatives from the acylation reaction of respective trialkyl orthoacetates and orthopropionates with trichloroacetyl chloride in good yields, is reported. The title compounds were used for the regiospecific preparation of two isoxazoles and five pyrazoles in the cyclocondensation with hydroxylamine and hydrazines, respectively. The transformation of the trichloromethyl group under mild conditions into carboxylic groups is also described.

A new method for beta-phenol annulation involving base-induced [4C + 2C] cycloaromatization of readily available 4-bis(methylthio)-3-buten-2-one with a variety of cyclic and acyclic active methylene ketones has been reported. Appropriate choice of ketones allows synthesis of diverse frameworks such as dihydroindan, tetrahydronaphthalenes, their higher homologues, dihydro/octahydrophenanthrenes, anthracene, and heteroannulated analogue in high yields with regiocontrol of phenolic functionality.

The Michael addition of β-keto esters to 3-buten-2-one (methyl vinyl ketone, MVK) in the presence of a pentacoordinate organosilicate was investigated. Ethyl 2-oxo-1-cyclohexanecarboxylate reacted with MVK in the presence of potassium bis(1,2-benzenediolato)phenylsilicate to furnish ethyl 2-oxo-1-(3-oxo-1-butyl)-1-cyclohexanecarboxylate in 96% isolated yield. Ethyl 2-oxo-1-cyclopentanecarboxylate, ethyl 2-oxo-1-cyclooctanecarboxylate, ethyl 2-methyl-3-oxobutanoate, and ethyl 2-ethyl-3-oxobutanoate also reacted with MVK in the presence of potassium bis(1,2-benzenediolato)phenylsilicate to produce the corresponding 1,4-adduct in moderate to good yields. In these reactions, the silicate might work as both a Lewis acid catalyst and a Bronsted base catalyst at the same time.

Synthetic procedures for preparing η2- and η4-complexes of chalcone and benzalacetone with hexacarbonyl mononuclear complexes of Group VIB metals were developed and conditions for selective η2- and η4-coordination of the heterodiene ligand were established. Hydrophosphorylation of the obtained complexes proceeds in the coordination sphere of the metal by the Abramov reaction scheme and yields the corresponding η2-coordinated α-hydroxyphosphonates. As follows from quantum-chemical calculations, π-coordination with metals makes the heterodienes no longer planar, which explains their regioselective phosphorylation by the more electrophilic carbonyl group.

The phenyl-, carbomethoxy-, and carboethoxy-hydrazones of (3E)-4-phenyl-3-buten-2-one [benzalacetone] were treated with excess lithium diisopropylamide, and the resulting 1,4-dianions were condensed with several aromatic esters, followed by acid cyclization of C-acylated intermediates, to afford substituted 3-(2-phenylethenyl)-1H-pyrazoles [3-styryl-pyrazoles].

A short and regioselective synthesis of γ-hydroxycyclohexenones is described, using 3- p -nitrobenzoyloxy-3-buten-2-one ( 2a ) as a ketene equivalent in Diels-Alder reactions with substituted dienes. Oxidation with MCPBA of the α-acetylcyclohexenol derivative, obtained by hydrolysis of the cycloadducts, led to the corresponding γ-hydroxycyclohexenones in moderate overall yields. Evidence of the mechanism is provided.

trans-4-Phenyl-3-buten-2-one (PBO), a flavoring additive, was transformed to the carbonyl-reduced product, trans-4-phenyl-3-buten-2-ol (PBOL) by rat liver microsomes, but not by liver cytosol, in the presence of NADH or NADPH. PBOL formed was identified by comparison with an authentic sample. The reductase activity was not inhibited by quercitrin, an inhibitor of cytosolic carbonyl reductase. The carbonyl reduction product of PBO by liver microsomes was identified as the R-enantiomer of PBOL by HPLC analysis. Rat blood also exhibited the carbonyl reductase activity in the presence of NADH or NADPH, but to a lesser extent.

A synthetic method for 1-bromo-3-buten-2-one is given. The compound is prepared through the following sequence: 2-butanone to 2-methyl-2-ethyl-1,3-dioxolane to 2-(1-bromoethyl)-2-bromomethyl-1,3-dioxolane to 2-bromomethyl-2-vinyl-1,3-dioxolane to the final product. Full experimental details including spectral data are given.

A toxicologic and dermatologic review of 4-(1,2-epoxy-2,6,6-trimethylcyclohexyl)-3-buten-2-one when used as a fragrance ingredient is presented.

Ionic liquids are substances that are completely composed of ions and are liquid at or close to room temperature. 1 Biocatalysis in ionic liquids media was first reported in 2000. In our studies towards the synthesis of chiral halohydrins using [bmim(BF4)] (water-miscible) and [bmim(PF6)] (water-immiscible), one of the approaches was the bioreduction of the correspondent α-haloenones mediated by Pichia stipitis, so as to generate two stereogenic centers in the same reaction.

In this paper, we report on the X-ray analysis of 5-butyl­thevinone (7α-acetyl-4,5α-epoxy-3,6-di­methoxy-5β-butyl-17-methyl-6α,14α-ethenoisomorphinan), C27H35NO4. This compound is the sole product of a Diels–Alder reaction of 5-butyl­thebaine with 3-buten-2-one, through attack of the dienophile on the β-face of the diene, even though it has been suggested that the introduction of 5β-substituents tends to hinder attack from the β-face, and leads to the production of exo-etheno adducts through attack from the α-face.

The Friedel-Crafts condensation of acetyl chloride and vinylidene chloride (1,1-dichloroethylene) in dichloromethane solution gives 4,4,4-trichloro-2-butanone (2), which is smoothly dehydrohalogenated with triethylamine to produce 4,4-dichloro-3-buten-2-one (1) in excellent yield

1-Bromo-3-buten-2-one is investigated as a building block for organic synthesis. Reduction to the corresponding alcohol works best with lithium aluminium hydride, reaction with primary amines gives 5-membered-aza-heterocycles in moderate yields and reaction with activated methylene compounds to form 5-membered-carbocycles gave unsatisfactory yields when a one-pot-procedure was used. The first step of a stepwise protocol, a Michael addition, is discussed.

Synthetic procedures for the preparation of 1-bromo-3-butyn-2-one and 1,3-dibromo-3-buten-2-one are given. These compounds are prepared from 2-bromomethyl-2-vinyl-1,3-dioxolane, which can readily be prepared from 2-ethyl- 2-methyl-1,3-dioxolane. The synthetic routes are as follows: 2-bromomethyl-2-vinyl-1,3-dioxolane is converted to 2-(1,2-dibromoethyl)-2-bromomethyl-1,3-dioxolane. Double dehydrobromination with tBuOK affords 2-ethynyl-2-bromomethyl-1,3-dioxolane. Formolysis with formic acid gives 1-bromo-3-butyn-2-one. Deacetalized 2-bromoethyl-2-vinyl-1,3-dioxolane was treated with Br2 and Li2CO3/12-crown-4 in tetrahydrofuran to give 1,3-dibrom-3-buten-2-one in moderate yield.

A toxicologic and dermatologic review of 4-(3,5,6-trimethyl-3-cyclohexen-1-yl)-3-buten-2-one when used as a fragrance ingredient is presented.

A toxicologic and dermatologic review of 3-methyl-4-(2,4,6-trimethyl-3-cyclohexen-1-yl)-3-buten-2-one when used as a fragrance ingredient is presented.

4-Ethoxy-1,1,1-trifluoro-3-buten-2-one reacts with triethyl phosphite on heating to give a [4 + 2 cycloaddition product 2,2,2-triethoxy 2,3-dihydro-3-ethoxy-5-trifluoromethyl-1,2λ 5 -oxaphospholene. Its hydrolysis yields, ultimately, a 2-oxo-2-hydroxy-2, 3-dihydro-3-hydroxy 5-trifluoromethyl-1,2λ 5 -oxaphospholen.

Novel heterocyclizations have been investigated based on the reaction of the complex between trifluoromethanesulfonic anhydride and 4-dimethylamino-1,1,1-trifluoro-3-buten-2-one with 2,2'-biindolyl and N,N'-dipyrrolylmethane leading to closure of 6- or 7-membered rings.

3-Trimethylsilyl-3-buten-2-one: A Michael acceptor intermediate: Vinyltrimethylsilane intermediate: (1-Bromoethynl)trimethylsilane intermediate: 3-Trimethylsilyl-3-buten-2-ol product: 3-Trimethylsilyl-3-buten-2-one Keywords: elimination, miscellaneous; Grignard and related reactions; halogenation, bromination; oxidation, CHOH CO; tetrahydrofuran; condenser, Liebig condenser

The crystal structure of 1,1-dimethoxy-4-phenylamino-4-methylthio-3-buten-2-one I, C13H17NO3S, has been determined. The title compound is packed in columns along the a axis. C(4), C(5), C(6) and nitrogen atoms in the structure are coplanar and π-delocalization exists in I. The tautomer enamino ketone of I is stablized by π-delocalization and intra-molecular hydrogen bond.

The title compound, C21H25BrN2O, was synthesized by the Heck reaction. Its crystal structure shows that there are π–π-stacking interactions between the two aromatic rings of the two neighboring mol­ecules in the unit cell. The C—I bond distance is 2.108 (4) A and the butene double-bond distance is 1.311 (4) A.

C 10 H 8 BrNO 3 , M r =270.08, orthorhombic, Pna2 1 , a=11.137 (1), b=17.361 (2), c=5.5641 (4) A, V=1075.8 (2) A 3 , Z=4, D x = 1.666 g cm -3 , F(000)=536, λ(Mo kα)=0.71073 A, μ=37.67 cm -1 , T=298 K, R=0.034 for 690 unique reflections with I≥3σ(I). The nitro group is coplanar with the C=C bond but the additional π bonding of the C=O group and the phenyl ring means that they are twisted relative to the C=C bond plane by about 90 and 79 o , respectively