bluuebunny/crossref_metadata_2025 huggingface dataset:
The metabolism of hydroxyanthranilic acids. Part IV: The isolation and some of the properties of 3‐hydroxyanthranilate oxygenase from monkey liver
Authors: Savage Nerina , Soldin S. J. , Levy P. R.
Published: September 2010

3‐Hydroxyanthranilate oxygenase was purified 250‐930 fold from a hitherto unexamined source, the cytoplasmic fraction of the liver of the African Vervet monkey. The purification steps included extraction, heating, ammonium sulphate fractionation, acetone precipitation, chromatography on Sephadex G‐100 and or G‐200 and calcium phosphategel treatment. Final preparations of the enzyme ranged in specific activity from 5.5‐24.4. Starch‐gel electrophoresis at pH 8.6 indicated protein heterogeneity but more than one of the protein bands was active. Attempts to separate these active forms on DEAE‐ or CM‐cellulose were not successful due to marked instability of the preparations. The enzyme from monkey liver also requires Fe+ + for activity and is protected from inactivation by the presence of dithiothreitol.

The Km for 3‐hydroxyanthranilate is 40μM.
Isomerization, disproportionation, methylation and sulfonylation in the reaction of polyalkylbenzenes with methanesulfonic acid
Authors: Willard E. G. , Cerfontain H.
Published: September 2010

The reaction of the three tri‐, the three tetra‐methylbenzenes, 1,3,5‐triethylbenzene, 1,3,5‐tri‐ and 1,2,4,5‐tetra‐isopropylbenzene with methanesulfonic acid, was studied at 180°. The tri‐ and tetra‐methylbenzenes react with formation of a mixture of hydrocarbons which, for long reaction times, contains all the polymethylbenzenes except toluene. Equilibrium isomer ratios for the di‐ and tri‐alkylbenzenes and the tetra‐methylbenzenes are reported. The hydrocarbon products are formed by intramolecular alkyl migration, transalkylation and dealkylation. The xylene equilibration takes place only by transmethylation.

The hydrocarbons are sulfonylated further and methylated by the methanesulfonic acid reagent. The sulfonylation is far less important with durene than with hemimellitene and m‐xylene.

The reactions are accompanied by tar formation.
Proton magnetic resonance studies of specifically deuterated cyclohexane compounds: Part III. Long‐range couplings (4JHH) in cyclohexane
Authors: Remijnse J. D. , Vandeginste B. G. M. , Wepster B. M.
Published: September 2010

The preparation of 1,1,3‐triprotoperdeuterocyclohexane is reported. The low‐temperature PMR spectrum of this compound shows a superposition of two 3‐spin systems, originating from the two chair conformations. A long‐range coupling constant between the equatorial protons at positions 1 and 3 of 1.7 Hz is derived. The coupling between the 3‐axial proton and the 1‐protons is smaller than 0.4 Hz.
New reactive intermediates from carbon‐sulfur bond cleavage in heterocyclic compounds
Authors: Hoff S. , Blok A.P. , Zwanenburg E.
Published: September 2010

The sulfur‐carbon bond cleavage with alkali metals in liquid ammonia has been investigated in several heterocycles. Special attention has been paid to substituted 1,4‐thiazin‐3‐ones VIII in which the carbon‐sulfur bond is cleft selectively with formation of the dianion X. The protonation, alkylation and acylation of the alkenethiolates X and XI have been studied. Routes to the synthesis of 2,3‐dihydro‐4H‐1,4‐thiazine XIX and tetrahydro‐1,4‐thiazepine XX have been developed.
Chemistry of acetamidoalkenethiolates III. Synthesis of substituted 1,4,2‐oxathiazines and 1,3,4‐thiadiazines
Authors: Hoff S. , Zwanenburg E.
Published: September 2010

Substituted 6‐acetamido‐5,6‐dihydro‐1,4,2‐oxathiazines and 5‐acetamido‐5,6‐dihydro‐1,3,4‐thiadiazines have been prepared in high yields from sodium 2‐acetamidoalkenethiolates by reaction with hydroximic acid chlorides and hydrazonic acid chlorides, respectively. The scope of the reaction has been explored. The conformation of the 1,4,2‐oxathiazines has been proposed on the basis of PMR‐spectroscopic data.
13C N.M.R. and charge distribution in arylcyclobutenyl cations. Part II
Authors: van der Hout‐Lodder S. A. E. , de Haan J. W. , van de Ven L. J. M. , Buck H. M.
Published: September 2010

13C N.M.R. spectra of I, II, III, IV and V have been measured and a number of important assignments made. The resulting chemical shifts are correlated with calculated charge densities. Compound IV has been compared with the tetraphenylcyclobutadiene dication in the literature.
α,β‐Unsaturated acetals: Synthesis and mechanism of formation
Authors: de Leeuw J. W. , de Waard E. R. , Beetz T. , Huisman H. O.
Published: September 2010

The conversion of α,β‐unsaturated enones (6) to α,β‐unsaturated acetals (7) is described. The formation is shown to proceed via displacement of H2O in the intermediate hemiacetal. Fumaric acid is shown to be the catalyst of choice for the reaction from 6 to 7.
Structure and conformational equilibration of protonated tertiary alkanoic acids in HF solution
Authors: Brouwer D. M. , Kiffen A. A.
Published: September 2010

The most stable conformations of some protonated tertiary carboxylic acids in HF‐BF3 and HF‐SbF5 have been shown to be those which have one OH proton syn and the other anti to the alkyl groups. In HF solutions, the intramolecular interconversions between the two degenerate conformations is much faster with tertiary than with secondary or primary carboxylic acids; with the tertiary acids it is likely to proceed via the trans‐trans rather than the cis‐cis con‐former as an intermediate. The conformational equilibration of protonated pivalic acid is much faster in HF solution than in FSO3H‐SbF5‐SO2ClF solution.
Proton catalysed hydride transfer from alkanes to methylated benzyl cations: Part I: Kinetics
Authors: van Pelt P. , Buck H. M.
Published: September 2010

Hydride transfer from isoalkanes to methylated benzyl cations in strong proton acids and proton exchange between isoalkanes and strong proton acids have comparable velocities. The rate of proton exchange between isobutane and several strong proton acids has been studied by PMR line broadening and the following parameters were obtained: (with HSO3F) ΔH≠ = 5.5 kcal/mole., ΔS≠ = ‐35 cal/mole.°K; (with CF3SO3H) ΔH≠ = 4.3 kcal/mole., ΔS≠ = ‐43 cal/mole.°K.

Using 2‐2H‐isobutane and tritiated HSO3F, labelled hexamethylbenzene was prepared via hydride transfer to pentamethylbenzyl cations at various temperatures. The analyses for deuterium and tritium were combined with the known rates of proton exchange to get an estimate for the rate of hydride transfer and the corresponding activation parameters: ΔH≠ = 1 kcal/mole., ΔS≠ = ‐46 cal/mole.°K.
Conjugation in thiophene dioxides: Vibrational frequencies and hydrogen bonding ability
Authors: de Jong F. , Janssen M. J.
Published: September 2010

The interaction of the sulfonyl group with an adjacent unsaturated centre has been studied by IR spectroscopy. The sulfur‐oxygen stretching frequencies of thiophene dioxides are compared with those of the open‐chain counterparts. The observed differences indicate a small contribution of “ketonic” type of resonance to the ground state of thiophene dioxides. The same result is obtained using the internal relationship between SO stretching frequencies and hydrogen bonding abilities.

Qualitatively, these experimental results are in good agreement with the characteristics of the SO2 moiety, as obtained from HMO calculations.
Nucleophilic substitution of aromatic bromine in 2‐bromobenzophenone by Grignard reagents
Authors: Jongsma C. , Bickelhaupt F.
Published: September 2010

The reaction of 2‐bromobenzophenone (1) with methyl, ethyl, and phenyl Grignard reagents was found to involve substantial substitution of bromine by the organic group of the Grignard reagent It is shown that substitution occurs by intramolecular nucleophilic substitution of a ketone‐Grignard complex (9). The mechanistic implications of this reaction are discussed.
Chemistry of cyclopropene III: Synthesis of mono‐ and dialkylated cyclopropenes
Authors: Schipperijn A. J. , Smael P.
Published: September 2010

A simple method has been developed for the preparation of 1‐monoalkyl‐ and 1,2‐dialkyl‐cyclopropenes from cyclopropene and alkyl halides which is in many instances superior to those reported in the literature. High product yields are obtained with primary β‐unsubstituted halides and moderate yields when primary β‐monosubstituted halides are employed. The method is not applicable to primary β‐disubstituted, secondary and tertiary halides. In principle it can also be used for the synthesis of alkylcyclopropenes that bear functional groups in the carbon chain.

The strain‐releasing migration of the double bond in the cyclopropene product from the endocyclic to the exocyclic position can, in most cases, be successfully prevented by choosing proper reaction conditions.
Transition‐metal‐catalysed cheletropic elimination of carbene and oxygen from seven‐membered ring systems
Authors: Volger H. C. , Hogeveen H. , Roobeek C. F.
Published: September 2010

In the presence of catalytic amounts of [Rh(CO)2Cl]2 the monomethylene adduct of hexamethylbicyclo[2.2.0]hexa‐2,5‐diene (1) can be quantitatively converted into hexamethylbenzene and a monomethylene carbenoid species; the latter can be trapped by cyclohexene. The hexamethylbenzene is presumably formed via (a) catalysed electrocyclic opening of the cyclobutene ring in coordinated 1 to give coordinated hexamethylnorcaradiene, and (b) extrusion of the carbenoid species. The proposed reaction pathway is supported by the fact that penta‐ and hexamethylcycloheptatriene are also subject to the extrusion reaction in the presence of the catalyst. Under the same catalytic conditions 1,6‐dimethyl‐oxepine is quantitively converted into o‐xylene.

Apart from the aromatization the catalyst effects double‐bond isomerization of the methyl‐substituted cycloheptatrienes.
Synthesis of β‐phenylethylamine derivatives XN‐(hydroxy‐ and methoxy‐aralkyl) derivatives
Authors: van Dijk J. , Moed H. D.
Published: September 2010

The synthesis and some pharmacological properties are described of compounds of the general structure:

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The series contains strong and/or selective utero‐relaxing agents. Stereoisomers of two interesting compounds were separated and characterized, and their configurations were established.
Chemistry of sulfonyl cyanides. Part 4: Diels‐alder cycloadditions of sulfonyl cyanides with dienes
Authors: Jagt J. C. , van Leusen A. M.
Published: September 2010

Tosyl cyanide reacts under extremely mild conditions with 2,3‐dimethyl‐1,3‐butadiene, isoprene and, under somewhat different conditions, with 1,3‐butadiene. The products, 2‐tosylpyridines and 3,6‐dihydro‐2‐pyridones, are derived by dehydrogenation and hydrolysis, respectively, of the Diels‐Alder cyclo‐adducts formed in situ. Phenylmethanesulfonyl cyanide and 1‐adamantane‐sulfonyl cyanide give analogous results with 2,3‐dimethylbutadiene.

At 175°C, tosyl cyanide and tetracyclone form 3,4,5,6‐tetraphenyl‐2‐tosylpyridine. Phenylmethanesulfonyl cyanide and p‐chlorobenzenesulfonyl cyanide react similarly.
Chemistry of acetylenic ethers 103 Stereospecific addition of Grignard compounds to 1‐alkynyl sulfides in the presence of copper(I) halide
Authors: Vermeer P. , de Graaf C. , Meijer J.
Published: September 2010

Excellent yields of vinylic sulfides R1R2CCHS‐CH3are produced in acis‐addition reaction, from 1‐alkynyl sulfides R1CCS‐CH3and Grignard compounds R2MgX under the influence of copper(I) halide in tetrahydrofuran.
Folded conformations. Part VI. An NMR spectroscopic study of the preferred solution conformation of N,N′‐[bis(α‐tosylbenzyl)]urea
Authors: Tel R. M. , Engberts Jan B. F. N.
Published: September 2010

Comparison of NMR spectral data of a number of N‐tosylalkyl‐ and N,N′‐bis(tosylalkyl)ureas reveals that the methyl protons of the tosyl moiety and the α‐sulfonyl alkyl proton in the N,N′‐[bis(α‐tosylbenzyl)]ureas 1‐3 resonate at unusually high fields. The presence of both sulfonyl groups and the aromatic rings of the benzyl moieties are prerequisites for the observation of appreciable upfield shifts. Evidence is presented that intramolecular shielding phenomena are involved. It is proposed that 1‐3 in solution predominantly adopt conformations in which each tosyl methyl group is positioned in the shielding region of the phenyl ring of the most remote benzyl group.
Electrochemical hydrocoupling of 2‐alkanones with ethyl acrylate and acrylonitrile
Authors: Fröling A.
Published: September 2010

4‐Methyl‐4‐alkanolides can be prepared by electrochemical hydrocoupling of 2‐alkanones with ethyl acrylate. Good yields are obtained up to 2‐heptanone; 2‐octanone gives moderate yields, whereas 2‐undecanone does not couple at all, indicating the limit of this method. Information on the course of these coupling reactions, including the optimum electrode potential, was obtained from cyclic voltammetric investigations.
The crystal structure and absolute configuration of the 3‐p‐iodobenzoate‐11‐acetate of secogorgosterol
Authors: Enwall E. L. , van der Helm Dick
Published: September 2010

The crystal and molecular structure of a cyclopropane containing marine steroid, secogorgosterol and its absolute configuration have been determined by single X‐ray diffraction studies on the 3‐p‐iodobenzoate‐11‐acetate derivative. The compound crystallizes in space group PI with reduced cell dimensions a = 9.58, b = 16.38, c = 9.80, α = 96.71, β = 139.75, γ = 94.29. There is one formula unit (C39H55O5I) per unit cell (Z = I). Crystal data were obtained on a G.E. XRD‐5 diffractometer using the moving‐crystal, moving‐counter method, and the structure refined by least squares methods to a conventional R of 6.7% on all (2409) data. The structure determination confirms the presence of a cyclopropane ring in the side chain of the gorgosterol system while a trans conformation is observed about the 22‐23 bond.
Selective halogenation using molecular sieves
Authors: van Dijk J. , van Daalen J. J. , Paerels G. B.
Published: September 2010

On treatment of aromatic compounds, entirely adsorbed in type X molecular sieves, with bromine or chlorine a selective halogenation is found to take place. Alkylbenzenes give mainly ‐ and halogenobenzenes almost exclusively ‐ the para isomers. The bromination of alkylbenzenes takes place only in the ring. Phenyl ethers undergo a strong deactivation of the aromatic ring.

In halogenations of toluene and halogenobenzenes, the use of catalytic amounts of CaX in which in most cases part of the cation is exchanged by Fe+++, result also in a significantly higher para/ortho ratio, than in reactions homogeneously catalyzed by FeCl3.
Alkyl α‐bromoalkanecarbodithioates Preparation and reaction with some nucleophilic reagents
Authors: Wesdorp J. C. , Meijer J. , Vermeer P. , Bos H. J. T. , Brandsma L. , Arens J. F.
Published: September 2010

Dithiocarboxylic esters, R1R2CHCSSCH3 (R1 and R2 = H or CH3), can be converted into α‐bromodithio esters, R1R2C(Br)CSSCH3, by reaction with the complex of bromine and dioxane. The results of a preliminary study of the type of reaction between (CH3)2C(Br)CSSCH3 and some nucleophilic reagents are reported.
Hydrogenolysis of 2,4,6‐tris(aryloxy)‐s‐triazines over palladium: A new method for the replacement of phenolic hydroxyl groups by hydrogen
Authors: van Muijlwijk A. W. , Kieboom A. P. G. , van Bekkum H.
Published: September 2010

Hydrogenolysis of a series 2,4,6‐tris(aryloxy)‐s‐triazines (obtained from cyanuric chloride and the corresponding phenols) over palladium on carbon gave the corresponding arenes in excellent yields.

The rate of hydrogenolysis is not influenced by the electronic character of the substituents; increase in the size of the substituents retards the reaction.

Both base and catalyst support were found to promote the reaction and their role in the hydrogenolysis reaction has been studied.
13CMR analysis of methyl octadecenoates
Authors: Bus J. , Frost D. J.
Published: September 2010

Carbon‐13 magnetic resonance spectra have been measured of methyl cis‐ and trans‐octadecenoates with the double bond positions 8, 9, 10, 11 and 12.

The chemical shift of the allylic carbon atoms displays a large dependence on the stereochemistry of the double bond: δ ≈︁ 27.3 ppm for the cis and δ ≈︁ 32.6 for the trans configuration. The difference in chemical shift between the two ethylenic carbon absorptions increases significantly as the double bond approaches the ester group. Thus, the position as well as the configuration of the double bond in methyl 8‐ up to 12‐octadecenoates can readily be established by 13CMR.
Ring transformations in reactions of heterocyclic compounds with nucleophiles (IX). Conversion of N‐methylpyrimidinium salts in pyridines by carbanions
Authors: Oostveen E. A. , van der Plas H. C.
Published: September 2010

On treatment with active methylene compounds in basic media the quaternary pyrimidinium salts, i.e. methyl l‐methylpyrimidinium sulfate, 1‐methyl‐4‐phenylpyrimidinium iodide and 1‐methyl‐5‐phenylpyrimidinium iodide are converted into pyridine derivatives. The mechanism of the reaction is discussed.
Studies on organophosphorus compounds ‐ VII. Synthesis of phenolic esters of N,N‐dimethylphosphoramidic acids and N,N‐dimethylphosphoramidochloridic acid from hexamethylphosphoric triamide
Authors: Perregaard J. , Pedersen E. B. , Lawesson S.‐O.
Published: September 2010

Heating hexamethylphosphoric triamide (HMPA) with phenols at about 230° for 20‐30 hours yields a mixture of mono‐ and di‐substituted esters of phosphoramidic acidsP(O)(NMe2)n‐(Oψ3‐n n = 1,2 and in some cases rather high yields of triesters of phosphoric acid are isolated. The distribution of products varies with the structure of the phenols and the relative amount of HMPA. Some phenols do not give the expected phosphoramidic acids, but the corresponding N,N‐dimethylanilines.

In the presence of HCl phenols react with an excess of HMPA to give fairly good yields of phenolic esters of N,N‐dimethylphosphoramidochloridic acid, P(O)(Cl)(NMe2)(Oψ).
Synthesis and reactions of 3,5‐dichloro‐4H‐1,2,6‐thiadiazin‐4‐one
Authors: Geevers J. , Trompen W. P.
Published: September 2010

Treatment of 3,4,4,5‐tetrachloro‐4H‐1,2,6‐thiadiazine (1) with formic acid affords the title compound 2 in high yield. Replacement reactions of 2 with various N‐, O‐and S‐nucleophiles are described. The structure of the thiadiazine ring in the compounds prepared is discussed.
Ring transformations in reactions of heterocyclic halogeno compounds with nucleophiles (XXXVIII). The influence of leaving group mobility on reactions of 4‐X‐6‐methyl (or phenyl)‐pyrimidine 1‐oxides with liquid ammonia and with potassium amide in liquid ammonia
Authors: Peereboom R. , van der Plas H. C.
Published: September 2010

The influence of leaving group character on ring contraction and amination in reactions of 4‐X‐6‐R‐pyrimidine 1‐oxides [X=Cl, Br, I, SC6H5, OC6H5, N⊕ (CH3)3, and RCH3 or C6H5] with liquid ammonia at − 33°C and with potassium amide in liquid ammonia at − 75°C has been investigated. The rate of C(4) addition decreases in the series N⊕(CH3)3 > Cl, Br, I > OC6H5, SC6H5, being qualitatively in accordance with the leaving group mobility order. The influence of leaving group activity on the ring contraction followed the reverse order.
The chemistry of small ring compounds. Part 25. 1‐Acetoxycyclopropanol, a convenient precursor for cyclopropanone
Authors: van Tilborg W. J. M. , Steinberg H. , de Boer Th. J.
Published: September 2010

The acetoxy group in 1‐acetoxycyclopropanol can be replaced easily by various nucleo‐philes (e.g. CN, N3, NR2, OR, SR). Such reactions proceed via cyclopropanone, which is present together with acetic acid, in a small equilibrium concentration. It is shown that the use of 1‐acetoxycyclopropanol as a practical source of highly reactive cyclopropanone has many advantages over that of the latter.

The ability of 1‐acetoxycyclopropanol to give cyclopropanone, ‐ in contrast to many other 1‐substituted cyclopropanols ‐, is due to the strong intramolecular hydrogen bridge between the hydroxyl and the acetyl group, as shown by infrared and NMR studies.
The chemistry of small ring compounds. Part 26. The chemistry of 1‐(dimethylamino)cyclopropanol
Authors: van Tilborg W. J. M. , Steinberg H. , de Boer Th. J.
Published: September 2010

The hydroxyl group of the title compound can easily be displaced by all common nucleophiles. The mechanism of such displacements is discussed in terms of an SN1 type reaction involving the cyclopropaniminium ion as an intermediate. An explanation is given why weak acids are good catalysts for such displacements, while mineral acids are poor.

The reaction of 1‐(dimethylamino)cyclopropanol with ketene and isocyanates leads to the formation of transient cyclopropanone. Ketene and isocyanates do not react simply with the hydroxyl group of 1‐(dimethylamino)cyclopropanol, but form derivatives of dimethylamine besides the liberated cyclopropanone.
The reaction of chlorodithioformates with Grignard reagents
Authors: Larsson F.C.V. , Lawesson S.‐O.
Published: September 2010

Ethyl and phenyl chlorodithioformate have been reacted at −20°C with phenylmagnesium bromide and p‐tolylmagnesium bromide to give substituted thioketones 4 in acceptable yields. The reaction between methyl chlorodithioformate and methylmagnesium iodide at −40°C gave dimethyl trithiocarbonate and 3,3,7,7‐tetrakis(methylthio)‐1,2,4,6‐tetrathiepane‐5‐thione (8). When the reaction took place at 0°C other compounds also were isolated in small yields.
A synthesis ofcis‐6‐alken‐4‐olides
Authors: Russell S. W.
Published: September 2010

cis‐6‐Alken‐4‐olides have been prepared by coupling the Iotsich complex of 1‐alkynes with epichlorohydrin to give chlorohydrins which are dehydrochlorinated to 1,2‐epoxy‐4‐alkynes. Condensation of these with sodium diethyl malonate in dimethylformamide gives the (ethoxycarbonyl)acetylenic lactones which are saponified and decarboxylated to give 6‐alkyn‐4‐olides. Reduction with hydrogen over Lindlar's catalyst furnishes the title compounds.
The manganese(III) acetate initiated synthesis of carboxylic acids from α‐olefins and acid anhydrides
Authors: de Klein W. J.
Published: September 2010

Under appropriate conditions manganese(III) acetate can be used as a free radical initiator to effect the addition of acid anhydrides to α‐olefins in a chain reaction. This results in an efficient synthesis of straight chain or α‐branched carboxylic acids. In this reaction manganese(III) acetate compares favourable with known peroxidic initiators. A mechanistic scheme accounting for the observed products is proposed.
The chemistry of small ring compounds. Part 30. Reactions of arylcyclopropanone hemiacetals with bases and acids
Authors: Bakker B.H. , van Ramesdonk H.J. , Steinberg H. , de Boer Th. J.
Published: September 2010

The arylcyclopropanone methyl hemiacetals (aryl = C6H5, p‐ClC6H4 and p‐CH3C6H4) are quantitatively isomerised by sodium methoxide or tert‐amines to propionic esters. The ring fission is rapid and occurs exclusively at the C1‐C2 position, leading to products derived from the most stable incipient carbanion.

The hemiacetals react with acids via a Woodward‐Hoffmann cleavage of the C1‐C3 cyclopropyl bond, affording a mixture of 1‐ and 3‐substituted arylacetones, the ratio of which depends on the nature of the acid. This acid‐catalysed C2‐C3 ring‐fission only occurs when an aryl group is present. The unsubstituted cyclopropanone hemiacetal isomerises in (weak) acid to the propionic ester (C1‐C2 rupture).

The transformation of arylcyclopropanone methyl hemiacetals in acidified methanol to α‐aryl‐α‐methoxy‐acetones, is first order in the hemiacetal. From the rate constants a Hammett ρ value of −0.7 is obtained, thus showing a small interaction of the aryl group with the remote reaction centre. This is considered to support a mechanism in which arylcyclopropanone is an essential intermediate. Subsequent protonation of this ketone with simultaneous C2‐C3 bond rupture gives the substituted 2‐hydroxyallylic cation. For this step an approximate ρ value of −2.9 is calculated, thus indicating that this step is much more sensitive to the presence of a (para) substituent in the aromatic ring. Further evidence for the occurrence of an intermediate arylcyclopropanone is the alkoxy exchange in the starting material when CD3OD or n‐propanol is used as solvent. The proposed mechanism is also consistent with the observed stability of the corresponding arylcyclopropanone acetals under similar acidic conditions.
Methyl ligand transfer between platinum and palladium complexes
Authors: Visser Jacobus P. , Jager Willem W. , Masters Christopher
Published: September 2010

Methyl transfer, either between two platinum centres or from a platinum centre to palladium, is a facile process; the latter transfer allows the methyl group to undergo reactions which, under the same conditions, do not occur at the platinum centre.
Conformation of non‐aromatic ring compounds −91. Carbon‐13 nuclear magnetic resonance spectra of some mono‐ and di‐alkyl substituted glutaric anhydrides
Authors: Koer F.J. , de Hoog A.J. , Altona C.
Published: September 2010

Fourier transform carbon‐13 nuclear magnetic resonance spectra of glutaric anhydride and ten of its derivatives have been obtained and interpreted. The effects of alkyl substituents on the carbon shieldings of the glutaric anhydride skeleton are compared with similar effects obtained for alkylcyclohexanes and cyclohexanones. Some additivity parameters have been derived and are used to estimate the conformational equilibrium composition of 2‐methylglutaric anhydride. 3‐Alkyl substituted glutaric anhydrides display unusual high field chemical shifts of the carbon at the 3‐position.
Photochemical hydroxylation of 7,8‐dimethylalloxazine (lumichrome)
Authors: Duren R.R. , Dekker R.H. , Verbeek J.
Published: September 2010

Anaerobic irradiation of an aqueous acid solution of lumichrome (7,8‐dimethylalloxazine) initially leads to the formation of 9‐hydroxylumichrome (II), 5,10‐dihydrolumichrome (III) and 9‐hydroxy‐5,10‐dihydrolumichrome (IV) in equilibrium with lumichrome (I). Prolonged irradiation results in complete conversion of lumichrome into 9‐hydroxy‐5,10‐dihydrolumichrome (IV). The composition of the irradiated solutions has been analyzed from spectral data.
Model experiments on the construction of the ABE ring system of hetisine type diterpene alkaloids
Authors: van Der Baan J.L. , Bickelhaupt F.
Published: September 2010

The cyanopyridinediols 5 were C‐alkylated to the unsaturated six‐membered imides 6. The allyl derivatives 6c and 6d underwent Cope rearrangement to 8a and 8b, respectively. The latter was transformed to the bromohydrin 9a which, after protection of the hydroxyl group, was cyclized by base to 11a. Removal of the protecting group and oxidation afforded ketone 12, a simple model compound containing the ABE ring system of hetisine type diterpene alkaloids. Its synthesis appears suitable for extensions including the CD ring system.
Copper(II)‐catalyzed formation of decenoic acids from manganese(III) acetate and 1‐octene in acetic anhydride/acetic acid mixtures
Authors: de Klein W. J.
Published: September 2010

The reaction of 1‐octene with manganese(III) acetate in acetic anhydride/acetic acid mixtures in the presence of Cu(II) salts gives 4‐decenoic acid as a major product, together with some 3‐decenoic acid. The 4‐decenoic acid, after esterification, is shown to consist mainly of the trans‐isomer, some cis‐isomer being also present.

4‐Acetoxydecanoic acid, γ‐hexyl‐γ‐butyrolactone and decanoic acid are minor side products. A reaction mechanism is proposed.
Kinetics of the vinyl acetate synthesis from acetylene and acetic acid with a zinc acetate catalyst
Authors: Cornelissen A. E. , Valstar J. M. , van den Berg P. J. , Janssen F. J.
Published: September 2010

Differential and integral kinetic measurements were performed in order to estimate a reaction rate expression for the synthesis of vinyl acetate from acetylene and acetic acid. Zinc acetate on activated carbon was used as catalyst.

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The adsorption constant K3 has been calculated from integral reactor data.

Literature adsorption data together with rate data at not too low values of pHOAc could satisfactorily be explained by assuming that the C2H2 adsorption is the rate controlling step. At high conversions and low partial pressures of acetic acid the acetic acid‐adsorption becomes the rate controlling step and the mechanism changes.

In the rate expression k = k∞ exp(‐E/RT), with k∞ = 5.08 * 103 kmol·kg cat−1·sec−1·atm−1 E = 20.3 * 103 kcal·kmol−1 and K1 = exp(3.8 * 103/T − 8.6 atm−1). K3 = exp(‐8.4 * 103/T + 20.4 atm−1) for the molar feed ratio acetylene: acetic acid = 4.0 and K3 = 2.6 atm−1 for the ratio 1.5.
Chemistry of acetylenic ethers 110 a convenient synthesis of 1‐alkynyl ethynyl sulfides preparation of mono‐substituted 1,4‐dithiins, 1,4‐thiaselenins and 1,4‐thiatellurins
Authors: Zilverschoon A. , Meijer J. , Vermeer P. , Brandsma L.
Published: September 2010

1‐Alkynyl ethynyl sulfides RC≡CS‐C≡CH (2) are easily accessible starting from 1‐alkynyl trimethylsilylethynyl sulfides RC≡CS‐C≡CSi(CH3)3(1).

When compounds2are treated with sodium sulfide, selenide or telluride in methanol 1,4‐dithiins, 1,4‐thiaselenins and 1,4‐thiatellurins are obtained in good yields.
Chemistry of electron‐rich conjugated polyenes (II)Synthesis of 1,1‐dimethoxy‐ and 1,1,4‐trialkoxy‐1,3‐butadienes and of 1,1,6,6‐tetramethoxy‐1,3,5‐hexatriene
Authors: Scheeren J. W. , Marcelis A. T. M. , Aben R. W. , Nivard R. J. F.
Published: September 2010

Several poly‐unsaturated, conjugated ketene acetals (Table I) have been obtained by 1,2‐ or 1,4‐elimination of alcohol with potassium amide from unsaturated acetals or ortho‐esters having hydrogen in an allylic position. The products have properties similar to simple electron‐rich olefins as is apparent from their smooth addition reactions with alcohols.
The reactions between 1′,3′,3′‐trimethylspiro[2H‐1‐benzopyran‐2,2′‐indolines] and 1,1‐bis[4‐(dimethylamino)phenyl] ethylene; products and mechanism
Authors: Zwanenburg D.J. , Maas Th. A. M. M.
Published: September 2010

The reaction between 1′,3′,3′‐trimethylspiro[2H‐1‐benzopyran‐2,2′‐indoline] and its derivatives (3a‐e) and 1,1‐bis[4‐(dimethylamino)phenyl]ethylene (“Michler's ethylene”) (4) were studied. Depending on the reaction time, the isomeric products 2,2‐bis[4‐(dimethylamino)phenyl]‐4‐{2‐methylidene‐1,3,3‐trimethylindoline}chromans (7a‐e) or 1′,3′,3′‐trimethyl‐4‐{2,2‐bis[4‐(dimethyl‐amino)phenyl]vinyl}‐spiro[chroman‐2,2′‐indolines] (8a‐d) were obtained. With deuterium labelled “Michler's ethylene” and deuterated solvents the mechanism of this reaction was confirmed. Reaction of the 2,2‐bis[4‐(dimethylamino)phenyl]‐2H‐chromenes 10c,d and 1,3,3‐trimethyl‐2‐methylene‐indoline (9) furnished the dihydrospiropyrans 8c,d. Chromene 10c and 1,1‐bis(p‐methoxyphenyl)‐ethylene gave 2.2‐bis(4‐methoxyphenyl)‐4‐ [2,2‐bis[4‐(dimethylamino)phenyl]vinyl}chroman. No fast proton exchange was observed in any of the reactions we have studied.
Catalyse acide intramoléculaire dans l'hydrolyse des acétals I. Position du proton dans l'état de transition
Authors: Buffet C. , Lamaty G.
Published: September 2010

The hydrolysis of a series of carboxy and methoxycarbonyl acetals, (Ib ‐ IXb and Ia ‐ IXa) derived from substituted salicylic acids and benzaldehydes has been studied. A strong intramolecular acid catalysis has been observed in the hydrolysis of substituted carboxy acetals.

The values of the Hammett ρ coefficients measuring the influence of substituents located in the aldehyde and phenol moieties are respectively −2.95 and + 0.93.

Comparison with the ρ values obtained with methoxycarbonyl acetals indicates that the C–O bond is largely broken in the transition state. The Bronsted α coefficient for carboxy‐group catalysis is quite small, ∼0.2 ± 0.1, suggesting a low degree of proton transfer in the transition state.
A convenient synthesis of codeine and morphine
Authors: Beyerman H. C. , Lie T. S. , Maat L. , Bosman H. H. , Buurman E. , Bijsterveld E. J. M. , Sinnige H. J. M.
Published: September 2010

Acid‐catalysed cyclization of 1‐(3,5‐dihydroxy‐4‐methoxybenzyl)‐N‐formyl‐1,2,3,4,5,8‐hexahydro‐6‐methoxyisoquinoline (2c), where the benzyl group is symmetrically substituted, gave N‐formyl‐2‐hydroxynordihydrothebainone (4c) exclusively. The 2‐hydroxyl substituent could be removed selectively in high yield, via the 1‐phenyltetrazol‐5‐yl ether (4d), to yield N‐formylnordihydrothebainone (4e). (‐)‐N‐Formylnordihydrothebainone (4e) was reduced to (‐)‐dihydrothebainone (4a). The conversion of 4a to codeine (1b) and morphine (1a) has already been recorded.
The chemistry of small ring compounds. Part 31 Thermolysis of some substituted (o‐hydroxyphenyl)cyclopropanes
Authors: van der Vecht J. R. , Spoor R. M. , Steinberg H. , de Boer Th. J.
Published: September 2010

Cyclopropanes 1b, 1c and 1d, carrying an o‐hydroxyphenyl group as a proton donor and ‐ at the same small ring carbon atom ‐ a potential proton acceptor X = NMe2, OMe or SMe, have been thermolysed. Between 350° and 600° cyclopropyl‐ring opening takes place with isomerization to substituted (o‐hydroxyphenyl)propenes 8b, 8c and (mainly) 8d, each of which can be hydrolysed to o‐hydroxypropiophenone 2. Only when X = SMe, does protonation on sulfur lead to formal MeSH elimination. A similar reaction is also found when X = Me3N⊕, thus sharply contrasting with X = Me2NH⊕.
Stereospecific addition of organocopper(I) reagents to 1‐alkynylphosphines. A new example of α‐hetero‐substituted vinylcopper(I) compounds
Authors: Meijer J. , Westmijze H. , Vermeer P.
Published: September 2010

Homocuprates R2CuMgX and heterocuprates [RCuBr]MgX can be reacted easily with 1‐alkynylphosphines R′‐C≡C‐P(C6H5)2 (R′ = H or CH3), leading exclusively to vinylic phosphines RR′CCHP(C6H5)2 after protonation, in almost quantitative yields. The additions proved to be stereospecific, only cis‐additions were observed as was shown by 1H‐NMR and GLC.
The crystal and molecular structure of dicyclopropylethanedione, C8H10O2
Authors: Lute C.N.A. , Statu C.H.
Published: September 2010

Dicyclopropylethanedione forms monoclinic crystals with cell constants: a = 6.317, b = 9.990, c = 6.078 Å and β = 90.34°. The space group is P21/n and there are two molecules in the unit cell. The molecules in the crystal are centrosymmetric with the CO groups trans with respect to each other. Each CO is cis relative to the adjacent cyclopropane ring (bisected conformation).
Pro‐oxidant effects of thiophenes: Sulfur‐dioxide‐catalysed hemolysis of hydroperoxides and oscillating oxidations
Authors: van Tilborg W.J.M. , Smael P.
Published: September 2010

In autoxidizing n‐hexylbenzene traces of SO2, evolved from “inactive” thiophenes or from other SO2 sources, give rise to an oscillating oxidation with oxygen evolution. This entirely new phenomenon is explained in terms of an SO2‐catalysed homolysis of hydroperoxides, which results in a very high initiation level.
Singlet‐oxygen oxidation of thiophenes
Authors: van Tilborg W.J.M.
Published: September 2010

Singlet‐oxygen oxidation of alkyl‐ and aryl‐substituted thiophenes has been studied with respect to product formation and relative rates of reaction. The reactivity of thiophenes towards singlet oxygen decreases with the introduction of electron‐withdrawing groups. A comparison of the nature of the products and the relative reactivities towards singlet oxygen of a number of thiophenes with their previously reported anti‐oxidant behaviour indicates that singlet oxygen plays hardly any significant role, if at all, in the desulfurization of thiophenes under autoxidative conditions.
Synthesis of the luteinizing hormone‐releasing hormone (LHRH) by the repetitive excess mixed anhydride (REMA) method
Authors: Beyerman H.C. , Rammeloo T. , Renirie J.F.M. , Syrier J.L.M. , van Zon A.
Published: September 2010

Using ethyl glycinate (I) as starting material, after Nα‐benzyloxycarbonyl‐nitroarginylproline [ZArg(NO2)‐Pro, II]* had been coupled to it with the aid of excess mixed anhydride, and after acidolysis, the tripeptide Arg(NO2)‐Pro‐Gly‐OEt was obtained. By means of the repetitive excess mixed anhydride (REMA) method the protected decapeptide sequence (X) of the luteinizing hormone‐releasing hormone (LHRH) was synthesized (Scheme). In the course of this process, at the heptapeptide stage, the C‐terminal ethyl ester (VIIa) was converted by ammonolysis into the amide (VIIb).

Acidolysis of X, with liquid hydrogen fluoride, gave crude LHRH (XI). Purification afforded LHRH, which was chemically identical with the luteinizing hormone‐releasing hormone synthesized elsewhere by another method, and which was found to be highly active biologically.
On the synthesis of 2,5‐dihydrothiophene
Authors: Everhardus R.H. , Gräting R. , Brandsma L.
Published: September 2010

2,5‐Dihydrothiophene can be obtained in reasonable yield by reaction of cis‐1,4‐dichloro‐2‐butene with anhydrous sodium sulfide in a mixture of methanol and dimethyl sulfoxide. The contaminating 3,4‐epithio‐1‐butene can be removed by reaction with excess of Na2S. 3,4‐Epithio‐1‐butene and 3,6‐dihydro‐1,2‐dithiin have been obtained in good yields by treating trans‐1,4‐dibromo‐2‐butene and cis‐1,2‐dichloro‐2‐butene with Na2S and Na2S2, respectively.
Derivatives of meta‐di‐tert‐butylbenzene. Part III: Preparation of some chlorinated derivatives
Authors: de Koning Adrianus Jan
Published: September 2010

The preparation of a number of chlorinated derivatives of meta‐di‐tert‐butylbenzene from 3,5‐di‐tert‐butylacetanilide and from 3,5‐di‐tert‐butylbenzoic acid is described.
Reversible binding of sulfur dioxide by polymer‐bound 1,3‐diene acceptor systems
Authors: Nieuwstad Th. J. , Kieboom A.P.G. , Breijer A.J. , van der Linden J. , van Bekkum H.
Published: September 2010

In connection with the removal of sulfur dioxide from waste and flue gases the use of polymer‐bound 1,3‐diene systems has been investigated. Using divinylbenzene/styrene copolymers as the solid support, a number of immobilized 1,3‐dienes were prepared; these were able to bind sulfur dioxide by the formation of the corresponding sulfolene systems. Heating of the latter resulted in liberation of sulfur dioxide with the concomitant recovery of the original 1,3‐diene system. In most cases, upon repeated use of the polymer‐bound 1,3‐dienes, a decrease of the sulfur dioxide binding capacity was observed. Probably, inter‐chain reactions of the diene groups are responsible for this phenomenon.
A facile and stereoselective approach to geminal endo‐iodo‐exo‐bromocyclopropanes; application in the synthesis of medium‐sized rings
Authors: Loozen Hubert J. J. , Robben Wil M. M. , Buck Henk M.
Published: September 2010

Geminal dibromocyclopropanes annelated to six‐, seven‐ or eight‐membered rings can be converted easily to their geminal endo‐lithio‐exo‐bromo derivatives when treated with butyllithium at −95°. Upon reaction of these derivatives with iodine at −95° the corresponding geminal endo‐iodo‐exo‐bromocyclopropanes are obtained in good yields. The structure assignments are made by means of some silver ion‐assisted ring expansions.
Preparation and photochemical electrocyclic reactions of quinoid γ‐oxo‐α,β‐unsaturated esters. Rearrangements to α‐alkoxy‐γ‐lactones
Authors: Mosterd A. , de Noten L. J. , Bos H. J. T.
Published: September 2010

A phenyl‐substituted γ‐oxo‐α,β‐unsaturated ester (3) was prepared by photochemical (2 + 2)‐cycloaddition of phenanthrenequinone (PQ; 1) to 1‐ethoxy‐2‐phenylethyne (2). A methyl substituted γ‐oxo‐α,β‐unsaturated ester 5 was prepared by boron trifluoride catalysed addition of PQ to 1‐methoxy‐1‐propyne (4). The γ‐oxo‐α,β‐unsaturated esters 3 and 5Z were rearranged to α‐alkoxy‐γ‐lactones 8 by a photochemical [4 + 2]‐electrocyclic reaction. Silica gel could bring about the same conversion of 5Z to 8.
Synthesis of thiophene‐containing steroid‐like molecules via olefinic cyclization reactions
Authors: Corvers A. , van Mil J. H. , Sap M. M. E. , Buck H. M.
Published: September 2010

Ring closure of 2‐methyl‐5‐(2‐thienyl)‐2‐pentene (4a) and 2‐methyl‐5‐(3‐thienyl)‐2‐pentene (4b) to the corresponding 4,5,6,7‐tetrahydrobenzo[b]thiophenes 5a respectively 5b, is described. In order to establish the possibility of the direct synthesis of steroids in which the A‐ring is replaced by thiophene, 2‐[6‐(2‐thienyl)‐(Z)‐3‐hexenyl]‐3‐methyl‐2‐cyclopenten‐1‐ol (9a) and its (3‐thienyl)‐substituted analogue (Z)‐ and (E)‐isomers 9b and 9c respectively, were prepared. The (Z)‐isomers failed to give tetracyclic compounds in contrast to 9c which furnished compound 14 in moderate yield.
Studies on polypeptides XX: Synthesis and biological activities of some des‐aspartylangiotensin II analogues
Authors: van Batenburg O. D. , de Graaf J. S. , Kerling K. E. T. , Havinga E.
Published: September 2010

Reported are the syntheses and the biological activities of (des‐Asp1)‐angiotensin II analogues (heptapeptides) in which the amino terminal arginine moiety is replaced by the following residues: L‐alanyl, D‐alanyl, L‐2‐amino‐4‐pentynoyl, D‐2‐amino‐4‐pentynoyl, glycyl, L‐2‐aminobutyryl and D‐2‐aminobutyryl. The results confirm the previously suggested hypothesis on the influence of the flexibility of the side chain on biological activity when the otherwise predominating terminal guanidino group is absent or replaced by an amino group.
The chemistry of small ring compounds. Part 37. Elimination of cyclopropanone from a tetraheteracyclooctanetetraspirocyclopropane (“SONO”)
Authors: Jongejan E. , van Tilborg W. J. M. , Steinberg H. , de Boer Th. J.
Published: September 2010

Bis(1‐hydroxycyclopropyl)methylamine 1 and bis(1‐hydroxycyclopropyl) sulfide 2 give on heating at 60° by dehydration the heteracycloalkanetri‐ and ‐tetraspirocyclopropanes SON and SONO (cf. Scheme 2). The total yield of these products is about 80%, whereas the yield of the heterocycles formed from 1, containing only N and O hetero atoms, remains below 10% (cf. Scheme 1). The compound SON is formed by elimination of cyclopropanone from SONO, presumably via S‐protonated SONO.
Novel pyrromethenes. 1‐Oxygen and 1‐sulfur analogues; evidence for photochemical Z‐E isomerization
Authors: van Koeveringe J. A. , Lugtenburg J.
Published: September 2010

Pyrromethenes [2‐(2‐pyrrylmethylene)‐2 H‐pyrroles] and 1‐oxygen and 1‐sulfur analogues with a minimum number of alkyl substituents can be synthesized under very mild conditions. Even the parent unsubstituted pyrromethene system can be prepared this way. After synthesis in the dark a Z‐configuration was established using N.O.E. measurements. A photochemical Z—E isomerization was detected (PMR spectroscopy) for derivates lacking an intramolecular hydrogen bridge.
A novel bromination for an unsaturated α‐anion ester. Synthesis of 2‐bromo‐cis‐8,cis‐11,cis‐14‐eicosatrienoic acid
Authors: van der Wolf Lodewijk , Pabon Henk J. J.
Published: September 2010

Electrophylic bromination via α‐anion esters (ester enolates) of polyunsaturated carboxylic acids has been achieved by the use of diethyl dibromomalonate as a mild source of positive bromine.

2‐Bromo‐cis‐8,cis‐11,cis‐14‐eicosatrienoic acid has been prepared, in 27% yield via the tert‐butyl ester. Final purification of the acid could be successfully attained only after application of ion‐exchange chromatography on DEAE‐cellulose.
A nuclear magnetic resonance spectroscopic study of ternary aqueous solutions. The use of bis(methylsulfonyl)methane as a probe for solute‐solvent interactions
Authors: Karzijn Willem , Engberts Jan B. F. N.
Published: September 2010

The present work reports chemical shift measurements fort‐BuOH/H2O, dioxane/H2O, CH3CN/H2O, THF/H2O and DMSO/H2O as well as for aqueous solutions ofn‐Bu4NBr and KBr containing bis(methylsulfonyl)methane (1) as a probe for solute/solvent interactions. For each ternary mixture the behaviour of the water resonance [v(H2O)] and the methylene proton chemical shift [v(CH2)] of 1 is given as a function of solvent composition. The trends ofv(H2O) are not affected by the presence of 1. Furthermore, the direction of the solvent‐induced shift ofv(CH2) in the water‐rich range is no general measure for the change in the solvent structural integrity. The shifts ofv(CH2) are determined by polar interactions (involving 1 as a hydrogen bonding donor as revealed by C‐D stretching frequency shifts for 1‐d2) and nonpolar interactions (including hydrophobic bonding). For dioxane/water especially there is strong evidence for preferential solvation of 1 by the apolar organic cosolvent. The data clearly reveal the complex features of aqueous ternaries. The solvent effects onv(CH2) are discussed in combination with kinetic and thermodynamic data for some slow proton transfer reactions. For DMSO/H2O thev(H2O) values at various mole fractions of water are linearly correlated withCox's data for the free enthalpies of transfer of a series of solutes from water to the corresponding DMSO/H2O mixtures.
Recueil des Travaux Chimiques des Pays‐Bas Journal of the Royal Netherlands Chemical Society: The adsorption of carbon monoxide and carbon dioxide in calcium‐exchanged zeolite Y
Authors: Michelena J. A. , Peeters G. , Vansant E. F. , de Bièvre P.
Published: September 2010

Adsorption of CO and CO2 has been studied on zeolite Y in which Na+ ions have been partially exchanged for Ca2+ ions. Physisorption of CO and CO2 provides a sensitive method for the observation of the population of Na+ and Ca2+ ions in supercage positions. The results indicate that Ca2+ ions introduced into a NaY zeolite by aqueous ion exchange preferentially enter sites in the small cavities on subsequent dehydration. When the degree of Ca2+ exchange stays below 35%, all the Na+ ions initially present in the small cavities as well as the incoming Ca2+ ions seem to remain inaccessible for CO and CO2 molecules.

However, a Na+ replacement of 35 to 45% leaves the Ca2+ ions unaffected by CO and CO2 but causes an important migration of inaccessible Na+ ions to accessible supercage positions. Further exchange (>45%) results in Ca2+ ions occupying locations exposed to the supercages. This work establishes that CO and CO2 are very sensitive probe molecules for investigating the location of unshielded mono‐ and divalent cations in zeolites.
Preparation of sulfines by chlorination of dithiocarboxylic esters
Authors: Veenstra G. E. , Bronold N. M. , Smits J. F. M. , Tangerman A. , Zwanenburg B.
Published: September 2010

A new and simple method for the conversion of the highly substituted arenedithiocarboxylates 1a‐d into the corresponding sulfines (thione oxides) 3a‐d by chlorination and subsequent hydrolysis is described.

The geometrical isomers of these sulfines are formed in the ratio 1:1. An excessive chlorination of the unhindered dithioesters 1e‐i results in (α,α‐dichloroaryl) sulfenyl chlorides 4, which can be converted into either thiobenzoyl chlorides by treatment with triphenylphosphine, or chlorosulfines by reaction with water and pyridine. Also an improved preparation of dichlorosulfine is described.
Dieckmann cyclisations in the synthesis of functionalised decalins
Authors: Peterse A. J. G. M. , de Groot Ae.
Published: September 2010

Reaction of ethyl 1‐methyl‐2,6‐dioxocyclohexanepropionate (8) with LiC=C‐OEt gives, after a rearrangement and an acetalisation, a cyclohexane derivative with a saturated and an unsaturated ester side‐chain (3). This diester can be cyclised in good yield to ethyl 5,5‐(ethylenedioxy)‐4a‐methyl‐2‐oxo‐3,4,6,7,8‐pentahydro‐1‐naphthalenecarboxylate (14).
Reaction of secondary N‐1‐(2‐chloroalkylidene)amines with lithium tetrahydridoaluminate: Synthesis and rearrangement of 1,2,2‐trisubstituted aziridines
Authors: de Kimpe Norbert , Verhé Roland , de Buyck Laurent , Schamp Niceas
Published: September 2010

1,2,2‐Trisubstituted aziridines have been prepared by reduction of secondary N‐1‐(2‐chloroalkylidene)amines with lithium aluminium hydride. N‐Substituted 1‐azaspiro[2.5]octanes (spiroaziridines) have been synthesized by this method. Under appropriate gas chromatographic conditions, 1,2,2‐trisubstituted aziridines underwent rearrangement to the corresponding secondary N‐1‐(alkylidene)amines. The reaction mechanisms are discussed.