The experimental detection of a retro-Prince reaction exemplified by a homogeneous acid-catalyzed decomposition of isopentenols

The occurrence of the retro-Prince reaction in the transformations of an equilibrium mixture of 2-methyl-3-buten-2-ol and 3-methyl-2-buten-1-ol in 24.9–49 % aqueous sulfuric acid at 25 °C has been experimentally proved.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 332–334, February, 1994.The work was carried out with the financial support of the Russian Foundation for Basic Research (Grant No. 93-03-18356).     

Kinetics and mechanism of the hydration of the equilibrium mixture of 3-methyl-1-buten-3-ol and 3-methyl-2-buten-1-ol with isoprene in aqueous solutions of sulfuric acid

The kinetic relationships of the hydration of an equilibrium mixture of 3-methyl-1-buten-3-ol (dimethylvinylcarbinol, DMVC) and 3-methyl-2-buten-1-ol (dimethylallyl alcohol, DMAA) with isoprene (C₅H₈) were investigated in aqueous solutions of sulfuric acid from 24.9 to 49.7% at 25°C. Data were obtained on the mechanism of hydration of the equilibrium mixture of DMVC and DMAA with isoprene.Deceased.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1311–1314, June, 1992.     

Condensation of 3-methyl-3-buten-1-ol with some ketones

The reaction of 3-methyl-3-buten-1-ol with acetophenone and benzalacetone affords a mixture of isomeric 2-methyl-2-aryldi- and tetrahydropyrans, the composition of which was ascertatined by chromatography-mass spectromety.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 883–885, July, 1986.     

Rate constants for the gas-phase reactions of Ozone with unsaturated Aliphatic Alcohols

The gas-phase reaction of ozone with unsaturated alcohols in air has been investigated at atmospheric pressure and ambient temperature (288–291 K). Cyclohexane was added to scavenge the hydroxyl radical which forms as a product of the ozone–unsaturated alcohol reaction. The reaction rate constants, in units of 10^?18 cm³ molecule^?1 s^?1, are 16.2 ± 0.7 for (±) 3-buten-2-ol, 17.9 ± 1.8 for 1-penten-3-ol, 10.0 ± 0.3 for 2-methyl-3-buten-2-ol, 169 ± 25 for cis-2 penten-1-ol, and 251 ± 41 for 2-buten-1-ol (mixture of isomers). Substituent effects on reactivity are discussed. The reactivity of unsaturated alcohols towards ozone is similar to that of their alkene structural homologues. Implications of these results with respect to the atmospheric persistence of unsaturated alcohols are briefly discussed. © 1994 John Wiley & Sons, Inc.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-and <Emphasis Type="Italic">C</Emphasis>-Alkenylanilines: VII. Synthesis of Indole Heterocycles from Products of Reaction between <Emphasis Type="Italic">N</Emphasis>-Mesyl-2-(1-alken-1-yl)anilines and Halogens

N-Mesyl-2-(1-methyl-1-butenyl)-6-methylaniline reacted with Br₂ to afford N-mesyl-2-(3-bromo-1-penten-2-yl)aniline that under treatment with NH₃ or amines underwent cyclization into N-mesyl-7-methyl-3-methylene-2-ethylindoline. The reaction of N-mesyl-2-(1-methyl-1-buten-1-yl)-4-methyl- and 2-(1-methyl-1-buten-1-yl)aniline with Br₂ gave rise to the corresponding N-mesyl-2-(2-bromo-1-methyl-1-buten-1-yl)anilines. Under the similar conditions N-tosyl-2-(1-cyclohexen-1-yl)aniline was converted into N-tosyl-2-(6-bromo-1-cyclohexen-1-yl)aniline that under treatment with NH₃ furnished N-tosyl-1,2,3,9a-tetrahydrocarbazole. The reaction of N-mesyl-1,2,3,9a-tetrahydrocarbazole with CuBr₂ in MeOH afforded N-mesyl-4-methoxy-1,2,3,4-tetrahydrocarbazole. N-Mesyl-6-methyl-2-(1-cyclopenten-1-yl)aniline in reaction with Br₂ in the presence of NaHCO₃ was oxidized into the corresponding cyclopentenone, and with NBS it gave N-mesyl-2-(2-bromo-1-cyclopenten-1-yl)aniline.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 5, 2005, pp. 730–737.Original Russian Text Copyright © 2005 by Gataullin, Sotnikov, Spirikhin, Abdrakhmanov.     

Preparative synthesis of isoprene oxide

The reaction of isoprene, hydrogen peroxide, and commercial hydrobromic acid gives 1-bromo-2-methyl-3-buten-2-ol, the low-temperature dehydrobromination of which gives isoprene oxide in high yield.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 736–737, June, 1989.     

Acetylene chemistry,part 32: Alkinylation and cyclic rearrangement of theophylline with unsaturated alcohols by Mitsunobu reaction

Summary The reaction of theophylline (1) with 2-methyl-3-butyn-2-ol and 1-butyn-3-ol under Mitsunobu conditions gave the respective 9-substituted derivatives 9-[2-(2-methyl-3-butynyl)]-theophylline (2) and 9-[2-(3-butynyl)]-theophylline (3). On reaction with 2-methyl-3-buten-2-ol, theophylline yielded in addition to the 9-[2-(2-methyl-3-butenyl)]-theophylline (4), two more cyclic products, identified as 1,5,5a,8-tetrahydro-1,3,8,8-tetramethyl-2H-pyrrolo[1,2-e]purine-2,4(3H)-dione (5) and 8a,9-dihydro-1,3,6,6-tetramethyl-1H-pyrrolo[2,1-f]purine-2,4(3H,6H)-dione (7).

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Acetylenchemie, 32. Mitt.: Alkinylierung und cyclische Umlagerung von Theophyllin mit ungesättigten Alkoholen mittels Mitsunobu-Reaktion

Zusammenfassung Die Reaktion von Theophyllin (1) mit 2-Methyl-3-butin-2-ol und 1-Butin-2-ol unter Mitsunobu-Bedingungen führte zu den 9-substituierten Derivaten 9-[2-(2-Methyl-3-butinyl)]-theophyllin (2) bzw. 9-[2-(3-Butinyl)]-theophyllin (3). Bei der Reaktion mit 2-Methyl-3-buten-2-ol ergab Theophyllin außer 9-[2-(2-Methyl-3-butenyl)]-theophyllin (4) noch zwei weitere cyclisierte Produkte, die als 1,3,8,8-Tetramethyl-1,5,5a,8-tetrahydro-pyrrolo[1,2-e]purin-2,4(3H)-dion (5) und 1,3,6,6-Tetramethyl-8a,9-dihydro-1H,6H-pyrrolo[2,1-f]purin-2,4-dion (7) identifiziert wurden.

     

Allylic oxidation of 1-methyl-1-cycloheptene

Conclusions The oxidation of 1-methylcycloheptene by SeO₂ and Hg(OAc)₂ gave a mixture of 1-hydroxymethyl-2-cyclohepten-1-ol and 3-methyl-2-cyclohepten-1-ol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2134–2136, September, 1986.     

Structure of [C3H5O]+ ions produced from unimolecular decomposition of several [C4H8O]+˙ metastable ions

It is demonstrated by means of collisionally activated decomposition (CAD) that [C₃H₅O]⁺ originating from metastable [C₄H₈O]^+˙ ions are either acylium [C₂H₅CO]⁺ (a) or hydroxycarbenium [CH₂CHCHOH]⁺ (b). Butanone gives exclusively a but 2-methyl-2-propen-1-ol, 2-buten-1-ol, 3-buten-1-ol, butanal and 2-methylpropanal lead to ion b. Both structures a and b are produced from 3-buten-2-ol. These results are discussed in conjunction with experimental and calculated (MINDO/3) thermodynamic data.     

Reactions on a surface. 1. Condensation of 3-methyl-3-buten-1-ol with carbonyl compounds on SiO2 and Al2O3

3-Methyl-3-buten-1-ol reacts with various aldehydes and ketones on silica gel and Al₂O₃ surfaces in the absence of solvents and conventional catalysts for this reaction to form derivatives of di- and tetrahydropyrans.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1326–1328, October, 1989.     

Kinetics and mechanism of hydration of 3-methyl-3-buten-1-ol in aqueous solutions of sulfuric acid

Conclusions The kinetic regularities of hydration of 3-methyl-3-buten-1-ol in 9.6 to 34% aqueous solutions of sulfuric acid at 25°C were studied. An equation was found for describing the influence of the medium on the value of the effective rate constant of hydration of 3-methyl-3-buten-1-ol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1016–1019, May, 1988.     

Isomerisation of ω-hydroxyalkenes under hydroxycarbonylation conditions in palladium catalysed aqueous phase systems

The ω-hydroxyolefins 3-buten-1-ol, 3-buten-1-methyl-1-ol and 4-penten-1-ol were subjected to hydroxycarbonylation conditions in water in the presence of PdCl₂(PhCN)₂ and 4-8 equiv. of water soluble tris(3-sodiumsulfonatophenyl)phosphine (TPPTS), or N-bis(N′,N′-diethyl-2-aminoethyl)-4-aminomethylphenyl-diphenylphosphine (N3P). Under conditions of high conversion, the olefins primarily undergo isomerisation through a chain walking mechanism with selectivities for aldehyde ranging from 65% to 98%, with the lower values for longer chain alcohols. The lactones formed as the minor product are almost exclusively branched, indicating that in the first step 2,1-insertion is strongly favoured over 1,2-insertion. In the N3P system also linear lactone is produced at lower conversion. Running the reaction in D₂O produces multiple deuterium incorporation in all positions of the carbon chain. A mechanism is discussed.     

Reactions on a surface. 2. Role of oxides in condensation of 3-methyl-3-buten-1-ol with aldehydes and ketones

The formation of di- and tetrahydropyrans on an oxide surface in the reaction of 3-methyl-3-buten-1-ol with carbonyl compounds is due primarily to the adsorptive properties of the surface itself, Lewis acid centers hardly catalyzing this reaction at all under the conditions being considered.See [1] for Communication 1 of the series.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 183–186, February, 1990.     

Synthesis of Drim-9(11)-en-8α- and -8β-ols from Drimenol

Drim-9(11)-en-8α-ol and drim-9(11)-en-8β-ol were synthesized in six steps from drimenol. Drimenol was oxidized by P₂O₅ and DMSO to drimenal, which isomerized with p-TsOH into isodrimenal. Isodrimenal was reduced by NaBH₄ into isodrimenol, epoxidation of which by m-CPBA gave a mixture (3.4:1) of α- and β-epoxyisodrimenols. These reacted with tosyl chloride in Py to give a mixture of α- and β-epoxyisodrimenol tosylates. Treatment of the tosylate mixture with KI and then Ph₃P produced a mixture of drim-9(11)-en-8α- and -8β-ols that was separated chromatographically. The overall yield was ∼26%.__________Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 152–155, March–April, 2005.     

trans-Bis-[(−)ephedrinate]-palladium complex: synthesis, molecular modeling and use as catalyst

The reaction between palladium acetate, (−)-ephedrine and potassium acetate led to bis-chelate complex Pd[OCH(Ph)NH(Me)]₂ whose the trans-structure is obtained from calculations. The use of this complex to catalyze either the 1,4-hydrogenation of (E)-2-benzyliden-1-tetralone or Heck reaction of phenyl iodide with 3-methyl-3-buten-2-ol led to a low enantiomeric excess.     

Synthèses de produits organofluorés VI Solvolyse de chlorofluorocyclopropanes

Fluoro-organic Syntheses VI: The Solvolysis of Chlorofluoro-cyclopropanes 2-Fluoro-allylic carbocations, generated from 1-chloro-1-fluoro-cyclopropanes or 2-fluoro-allyl p-toluene-sulfonates in water or acetic acid, undergo either proton loss or addition of hydroxyl or acetoxyl. In the latter case, an alkyl-substituted 2-fluoro-allyl ion leads predominantly to the more branched product (e.g. 3-fluoro-2-methyl-3-buten-2-ol) which may be converted into the less branched one (e.g. 2-fluoro-3-methyl-2-buten-2-ol) through reversible reactions.     

Benzo[f]-3-aza- and -10-azafluoroanthenes

Reduction of 3-methyl-9-(o-tolyl)-2-azafluoren-9-ol (I) with tin in hydrochloric acid gave 3-methyl-9-(o-tolyl)-2-azafluorene, dehydrocyclization of which on a K-16 catalyst at 520–500°C gave a complex mixture, from which four substances — 2-methylbenzo[f]-3-azafluoranthene, 11-methylbenzo[f]-10-azafluoranthene, benzo[f]-3-azafluoroanthene (II), and I-were isolated and identified by means of the IR, UV, and PMR, and mass spectra. It is shown that the dehydrocyclization proceeds through the hydrogen atoms of the methyl group of the tolyl substituent and takes place at the 8-C or 1-C atom of the azafluorene system. The formation of products II and I constitutes evidence that the reaction is accompanied by partial demethylation or oxidation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1245–1247, September, 1977.     

Pheromones of coleoptera. Communication 6. Synthesis of R,Z-14-methyl-8-hexadecenal (cis-trogodermal)

Conclusions The simple synthesis of optically active R,Z-14-methyl-8-hexadecenal (cis-trogodermal), the principal components of the aggregation pheromone ofTrogoderma granarium, was accomplished. The synthesis was based on the use of R-1-bromo-4-methylhexane and Z-4-chloro-2-buten-1-ol as the sources of the chiral and olefin fragments.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 906–910, April, 1987.     

Oxidation of isoprene by molecular oxygen in the presence of the tetraphenylporphin complex of divalent manganese

Conclusions The oxidation of isoprene proceeds regioselectively with the formation of 2-methyl-2-buten-1-ol. This oxidation is more rapid for isoprene than for 2-methyl-2-pentene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 214–215, January, 1986.     

Telomerization of allene with water catalyzed by palladium complexes

Conclusions The telomerization of allene with water catalyzed by palladium complexes leads to the preparation of 3-methyl-2-methylene-3-buten-1-ol and 2,3,6,7-tetramethylene-1-octanol in high yields.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2624–2626, November, 1985.