Oxymercuration. Substituted 9-oxabicyclo[4.2.1]- and 9- oxabicyclo[3.3.1]nonanes

Oxymercuration of cis, cis-1, 5-cyclooctadiene ( 1 ), followed by treatment with potassium iodide and subsequent reaction with iodine, leads to six isomeric diiodides which represent the three possible stereoisomers 2 , 3 , and 4 of 2, 5-diiodo-9-oxabicyclo[4.2.1]nonane as well as 5 , 6 , and 7 of 2, 6-diiodo-9-oxabicyclo[3.3.1]nonane. The isolation, structure determination and some reactions of these diiodo compounds 2 – 7 are described.     

Spectrométrie de Masse D'hétérocycles Séléniés. III—Etude de la Fragmentation de Quelques Selenolo [2, 3-b] Pyridines

The mass spectra of thirteen selenolo[2,3-b]pyridine derivatives have been measured and compared with those of benzo[b]selenophene, quinoline and thieno[2,3-c]pyridine. The influence of diheteroatomic structure of the nucleus on the mechanism of fragmentation of the oxygenated substituents is discussed.     

Systèmes aromatiques à 10 électrons π dérivés de l'aza-3a penlalène. VIII. Recherches dans la série du pyrazolo[3,2-c]-s-triazole

It has been shown that the reaction of β-ketoesters with 1,2-diamino-1,3,4-triazoles affords pyrazolo[3,2-c]-s-triazoles. These results induces us to propose a 7,8-dihydro-9H-s-triazolo[4,3–6]-[1,2,4] triazepin-8-one structure for the intermediate in this synthesis.     

Thiénopyrimidines VIII. Etude des thiéno[2,3-d] pyrimidinethiones

Substitution and addition reactions of thieno[2,3-d] pyrimidine-thiones have been studied. These reactions led to S- and N- substituted derivatives whose structure was established by the synthetic routes as well as by the ir and pmr spectra.     

Thio-I ehromannones 5,8-disubstituées et synthèses dans la série du thiéno[4,3,2-de] thiochromanne

With the aim of obtaining the thieno[4,3,2-de] thiochromane structure, various 5,8-disubstituted derivatives of [1]thiochromanone have been synthesized. The structures of the compounds thus obtained and of the intermediates used in their syntheses were confirmed by nmr spectroscopy or by chemical procedures.     

Etude de la réaction de l'acé'tylacé'tate d'éthyle avec les diamino-1,5 imidazoles

The condensation of 1,5-diaminoimidazoles with ethyl aceto-acetate gives two types of compounds: imidazo[1,5-b]-1,2,4-triazepinones and imidazo[4,5-b]pyridinones. The structure of these compounds is demonstrated by rmn and mass spectroscopy. The formation of imidazo[4,5-b]pyridinones from imidazo[1,5-b]-triazepinones through a new transposition is also shown.     

Stereochemie planarchiraler Verbindungen, 9. Mitt.

The two isomeric 1,6-methano[10]anulene carboxylicacid methylesters as well as 2,7-methano[10]azaanulene and several of its methyl, methoxycarbonyl and bromo derivatives have been separated into enantiomers by chromatography on triacetyl cellulose in ethanol; in seven from eleven cases baseline separation was achieved and thereby optically pure enantiomers obtained. The optical rotations and circular dichroism spectra of all anulenes were recorded. From chemical correlations and comparison of the CD spectra relative configurations were deduced; from chiroptical comparison with 2-methyl-1,6-methano[10]anulene of known absolute configuration and on the basis of the justmentioned correlations also absolute chiralities were tentatively proposed for the methano[10]azaanulenes.     

Lachnanthospirone,a dimeric 9-phenylphenalenone from the seeds of Lachnanthestinctoria ell.

The structure of lachnanthospirone [$\text{4}$] a novel dimeric pigment from $\text{Lachnanthes}$$\text{tinctoria}$ has been established from the X-ray crystal structure of a derivative [$\text{3}$] in which the spirolactone present in the natural product has been opened.     

Synthése par deux voies différentes d'un systéme dihétérocyclique apparenté aux peltogynoides

5-Oxo-5H,7H-[2]benzopyrano[4,3-b][1]benzopyran ( 2 ) has been synthesized from 3-(o-hydroxybenzylidene)isochroman-1,4-dione ( 3 ) by reductive cyclization, and from 5H,7H[2]benzo-pyrano[4,3-b][1]benzopyran-5,7-dione ( 4 ) by selective hydro-genation. This second method affords the dihydro compound 6 or 6a,12a-dihydro-5H,7H-[2]benzopyrano[4,3-b] [1 ]benzopyran-5-one as reaction time increases.     

Closed Pentaaza[9]helicene and Hexathia[9]/[5]helicene: Oxidative Fusion Reactions of ortho‐Phenylene‐Bridged Cyclic Hexapyrroles and Hexathiophenes

Oxidative fusion reactions of ortho ‐phenylene‐bridged cyclic hexapyrroles and hexathiophenes furnished novel closed helicenes in a selective manner. X‐Ray diffraction analysis unambiguously revealed the structures to be a closed pentaaza[9]helicene, the longest azahelicene reported so far, and an unexpected double‐helical structure of hexathia[9]/[5]helicene, whose formation was assumed to result from multiple oxidative fusion along with a 1,2‐aryl shift. The pentaaza[9]helicene exhibited well‐defined emission with high fluorescence quantum yield (Φ _F=0.31) among the known [9]helicenes. Chiral resolution of the racemic pentaaza[9]helicene and hexathia[9]/[5]helicene were achieved by chiral‐phase HPLC and the enantiomers were characterized by circular dichroism spectra and DFT calculations.     

Substitution directe de l'azote N-9 de la théophylline

In alkaline medium, 8-(2-chloroethyl)aminotheophylline (1) cyclizes into two imidazopurines: the imidazo[1,2-e]purine (2A) (cyclization on 9-N) and the imidazo[2,1-f]purine (2B) (cyclization on 7-N). The structure of each compound was determined by an unambiguous synthesis and confirmed by spectrographic methods. Synthesis of one pyrrlo[2,1-f]purine, a novel heterocycle, is described.     

Cycloadditions dipolaires-1,3 II. Addition des diarylnitrilimines au N-methyl-indole. Etude expérimentale et essai d'interprétation

The reactivity of N-methylindole towards diarylnitrilimines has been studies. The cycloadducts are 8-methyl-3a,8a-dihydro-pyrazolo[3,4-b] indole derivatives. The structure reported was assigned on the bases of satisfactory analytical, spectroscopic and chemical data. An interpretation based on the second order perturbation method of frontier orbitals is in agreement with the observed regiospecificity.     

Cyclic Acetal-Photosensitized Polymerization. 9. Photopolymerization of Triallylidene Sorbitol

Abstract

The photopolymerization of triallylidene sorbitol (TAS) was carried out in benzene at 40°C without the usual initiator. The polymerization of TAS was found to be initiated with the ester radical generated via the acetal radical from TAS by means of photoirradiation. The rate of polymerization and the molecular weight of polymer were small due to the degradative chain transfer, It was kinetically investigated from the standpoints of the degradative chain transfer by the allylidene group and the cyclization by three double bonds. The following results were obtained: (1) The relation between the rate of polymerization, R_p, the monomer concentration, [M], could be expressed by [M] /R_p = (A[M] + B)/(3[M] + C), where A, B, and C were constant; (2) the ratio of the rate constant of unimolecular cyclization to the total rate constant of bimolecular propagation and the chain transfer of uncyclized radical was estimated to be 3.0 mol/dm³. A small amount of cyclopolymerization took place.     

Mechanism of CO loss for protonated 1-indanone and isomeric [C9H9O]+ ions

In order to establish the mechanism of CO loss occurring during metastable decomposition of protonated 1-indanone, fragmentations of monocyclic [C₉H₉O]⁺ isomers have been studied. These ions of known structure were prepared by CI protonation and fragmentation of the corresponding acids chlorides. It is demonstrated that the wide component of the [MH? CO]⁺ metastable peak induced by protonated 1-indanone fragmentation is the result of fragmentation of the [C₆H₅CH₂CH₂CO]⁺ isomer ion.     

Pipérazinediones-2,5. 2. Les acides dioxothiazolidino pipérazine carboxyliques et leurs dérivés désulfurés

We have recently described a new synthetic route which has been used in our laboratory for the preparation of several novel heterocyclic systems comprising, the I,l-dimethylthiazolidino[3,4-o)piperazine-5,8- dione-3-carboxylic acid and the 2,2-dimethylthiazolidino[3,2-a]piper- azine-5,8-dione-3-carboxylic acid (8). The former was obtained with quan- titative yield and the latter with 71% yield. As a development of our studies on novel 2,5-piperazinedione systems, we describe in this report, the synthesis of the (2,5-dioxopiperazinyl)2-isobutyric acid (9), then-butyl(2-isopropyl)3,6-dioxopiperazinyl-l) acetate (1 l), and another synthetic route, illustrated in Scheme I, by which the compound 8 was obtained with quantitative yield. Spectrometric data were obtained and their interpretation confirms the proposed structure of the new compounds.     

Sur l'Utilisation de la Stéréospécificité des Couplages Magnétiques à Longue Distance dans la Détermination des Conformations d'Aziridines Bicycliques

The study of long range coupling constants in the ¹H NMR spectra (60 MHz) of aziridines with a 7-azabicyclo[4.1.0]heptane skeleton allows the determination of the conformation of these compounds and shows that some isomers have a rigid structure.     

Ionisation et Fragmentation en Spectrométrie de Masse. VII—Structure de l'Ion [C6H6O]+ Issu de la Décomposition du Phényléthyléther Sous Impact Electronique

The activation energy is calculated for the fragmentation [C₆H₅OC₂H₅]⁺ → [C₆H₆O]⁺ +C₂H₄. Estimation of the enthalpy difference between the final state and the molecular ion supports the formation of a phenol-like structure for the [C₆H₆O]⁺ ion. The activation energy for backward reaction is compared with the mean kinetic energy release. Whether this is a concerted or non-concerted fragmentation is discussed.     

Acetylenchemie. 9. Mitt. Anellierte imidazole aus N-propinylamid-vorstufen

The Compound 2-(N-Formyl-N-prop-2′-inyl)aminopyridine was cyclised in boiling formic acid to 3-methylimidazo[1,2-a]pyridine, with 3-methylene-2H-imidazo[1,2-a]pyridine as the intermediate. Under similar conditions the 1,3-diprop-2-inylpyrimido[4,5-b]quinoline-2,4-dione resulted from 1-methylimidazo[1,2-a]quinoline-4-carbonic acid-N-2-prop-2′-inylamide and from the 1-prop-2′-inylbenzo[b][1,8]naphthyridin-2-one the 1-methylbenzo[b]imidazo[1,2,3-ij]naphthyridine-4,7-dione as a new ring system, was obtained.     

Synthesis,structural and conformational study of some amides derived from 3,7-dimethyl-9-amino-3,7-diazabicyclo[3.3.1]nonane-9-carboxamide

A series of 3,7-dimethyl-9-amino-3,7-diazabicyclo[3.3.1]nonane-9-carbonitrile and 3,7-dimethyl-9-amino-3,7-diazabicyclo[3.3.1]nonane-9-carboxamide N-substituted have been synthesized and studied by ¹ H and ¹³C nmr spectroscopy and the crystal structure of 3,7-dimethyl-9-benzylamino-3,7-diazabicyclo[3.3.1]nonane-9-carboxamide dihydrochloride ( IVb· 2HCl) has been determined by X-ray diffraction. The compounds studied display in deuteriochloroform, dimethyl sulfoxide-d₆ and methanol-d₄ the same preferred flattened chair-chair conformation with the methyl groups in equatorial position. The carboxamido group lies in a plane nearly perpendicular to the bispidine skeleton. The conformation and protonation sites of IVb· 2HCl in the crystal state and in deuterium oxide solution are discussed.     

Ring transformations of heterocyclic compounds. XVI. Spiro[cyclohexadiene-dihydroacridines]. A novel class of spirodihydroacridines by ring transformation of pyrylium salts with 9-methylacridine and its quaternary salts

2,4,6-Triarylpyrylium salts 1 react with the in situ generated anhydrobase of 9,10-dimethylacridinium methosulfate ( 2a ) in the presence of anhydrous sodium acetate in ethanol by a 2,5-[C₄+C₂] pyrylium ring transformation to give the hitherto unknown 6-aroyl-3,5-diaryl-10′-methylspiro[cyclohexa-2,4-diene-1,9′-9′,10′-dihydro-acridines] 3 . When the pyrylium perchlorate 1a is treated under the same conditions with the N-ethyl, N-allyl or N-benzyl substituted acridinium salts 2b-d a dealkylation of these salts occurs and the N-unsubstituted spiro[cyclohexadiene-dihydroacridine] 4a is formed. The same compounds 4 can also be obtained by transformation of the pyrylium salts 1 with 9-methylacridine ( 7 ) and triefhylamine/acetic acid in ethanol. Structure elucidation is performed by an X-ray crystal structure determination of the spiro[cyclohexadiene-dihydroacridine] 3a . Spectroscopic data of the transformation products and their mode of formation are discussed.