Contribution à la connaissance des o-menthols et des o-menthones (carquéjanols et carquéjanones). 2e communication

(+)-Carquejanone and (-)-isocarquejanone have been described by their IR. spectra and configurationally studied by optical rotatory dispersion and circular dichroism (Cotton effect). The application of the octant rule confirms the configurations previously assigned by Thomas.     

Contribution à la connaissance des o-menthols et des o-menthones (carquéjanols et carquéjanones) - 1ère communication

The mixture of carquejanols obtained from carquejol of carqueja oil has been converted in ketones. The alkohols obtained respectively by hydrogenation on Pt(O₂), by lithium-aluminiumhydride reduction and by Meerwein-Ponndorf-Verley reaction have been separated by vapour phase chromatography. The ketones obtained from the Beckmann oxidation of the alkohols has been identified as carquejanone and isocarquejanone by application of the Auwers-Skita rule.     

Recherches sur la formation et la transformation des esters LXXIX [1]. Sur la réaction de l′isothiocyanate d′o-méthoxycarbonyl-phényle avec divers acides et l′acide sérinephosphorique

Amino acids devoid of «leaving groups» on their β carbon atom (neither ? OH: serine, nor ? SH: cysteine) react with o-methoxycarbonyl-phenyl isothiocyanate (I) in the presence of one equivalent of NaOH, in water-dioxane or in ethanol, to yield the corresponding hydroquinazolinone derivatives II which were isolated as free acids. When treated with CH₃COOH + conc. HCl the hydroquinazolinone resulting from the reaction of L -serine with I undergoes a nucleophilic attack of the carbon bearing the leaving group ? OH by a lone pair of electrons of S; this attack produces the formation of an additional thiazolidine ring, yielding the thiazoloquinazolinone derivative (?)-III. In an analogous reaction DL -serine phosphoric acid treated with I at pH 8–9 yields the corresponding substituted hydroquinazolinone which, boiled in 1N hydrochloric acid, undergoes ring closure to (±)-III by the same mechanism as the serine derivative (leaving group: ? OPO₃H₂). L -Cysteine reacted with 2 equiv. of I and then treated with CH₃COOH + conc. HCl gives two products: (?)-III produced by the same mechanism as for serine (leaving group: ? SH), and the quinazolinone derivative IV where the ? SH group is also thiocarbamoylated.     

Synthèse énantiospécifique des acides (+)-(2R)- et (−)-(2S)-éthyl-6-dihydro-3,4-méthyl-2-oxo-4–2H pyranecarboxylique-5

Enantiospecific Synthesis of (+)-(2R)- and (?)-(2S)-6-Ethyl-3,4-dihydro-2-methyl-4-oxo-2H-pyran-5-carboxylic Acid The two enantiomers (?)-(2S)- and (+)-(2R)-6-ethyl-3,4-dihydro-2-methyl-4-oxo-2H-pyran-5-carboxylic acid ((S)- and (R)- 7 ) have been synthesized from (+)-(3S) and (?)-(3R)-3-hydroxybutanoates, respectively (Scheme 1). By reduction and decarboxylation, the tetrahydro-2H-pyranols (2R, 4R, 6S)- and (2S, 4S, 6R)- 13 , respectively, were obtained with an enantiomeric excess of ≥ 93%.     

Etude dans la série des radicaux hétérocycliques. Partie XV. Décomposition aprotique de l'amino-6-éthyl-2-benzothiazole dans des substrats aromatiques et hétéroaromatiques: préparation des mésityl-6- et furyl-6-éthyl-2-benzothiazoles,des sels quaternaires et des spiropyrannes correspondants

Study of heteroaromatic radicals. Part XV .

1 Partie XIV: cf. [1].

Aprotic decomposition of 6-amino-2-ethylbenzothiazole in aromatic and heteroaromatic substrates: preparation of 6-mesityl- and 6-furyl-2-ethylbenzothiazoles and of the corresponding quaternary salts and spyropyrans In the presence of excess isopentyl nitrite in aprotic solvent, the 6-amino-2-ethyl-benzothiazole leads to 6-aryl- and 6-heteroaryl-2-ethylbenzothiazoles 1 to 14 in ca. 20–50% yield (Scheme 1, Table 1). The 2-ethyl-6-benzothiazolyl radicals generated during these reactions exhibit a weak electrophilic character (Table 2). Preparatively this method has been applied to the synthesis of 6-mesityl- and 6-furyl-2-ethylbenzothiazoles 6 and 7 , which were used to prepare the corresponding quaternary salts 15 , 16 and the spiropyrans 19, 20 (Scheme 4).     

Composés d'addition des chlorures de terres rares avec le méthanol,l'éthanol et le propanol-2. Préparations,solubilités et réactions de transsolvatation

By reaction of hydrated rare earths chlorides (M = La, Nd, Sm, Gd, Dy, Er, Yb, Y) with orthoformates, the following adducts have been prepared: MCl₃· 4MeOH, MCl₃ ·3EtOH (M = La, Nd, Sm, Gd, Yb), MCl₄ · 4 EtOH (M = Dy, Er, Y); adducts MCl₃ · 3iso-PrOH have been prepared by successive action of methyl orthoformate and of 2-propanol. The solubilities of these adducts in the corresponding alcohols at 25° (for the lanthanum adducts equally at 0 and 50°) are given. Two examples of the transsolvatation of these compounds, yielding adducts with weakligands, are described.     

Thermodynamique des mélanges liquides binaires. Volume de mélange d'alcanes normaux et ramifies

Volumes of mixing were determined by dilatometric measurements between 15° and 50°C for isomeric alkanes with n-hexadecane and n-dodecane. The negative excess volumes vary linearly with temperature.     

Synthèse des (−)-(6R)-et(+)-(6S)-tétrahydro-6-[(Z)-pent-2-ényl]-2H-pyran-2-one,lactones de Jasminum grandiflorum L. et de Polianthes tuberosa L.

Synthesis of (?)-(6R)- and (+)-(6S)-Tetrahydro-6-[(Z)-pent-2-enyl]-2H-Pyran-2-one, lactones from Jasminum grandiflorum L. and from Polianthes tuberosa L. (?)-(2S)-Ethyl 2-hydroxyhexanedioate ((2S)- 2 ) was obtained by kinetic resolution of racemic ethyl 2-hydroxy-hexanedioate with baker's yeast. The key intermediates (+)-(5R)- and (?)-(5S)-ethyl 5,6-epoxyhexanoate ((5R)- and (5S)- 6 , resp.) are proved to be useful synthons for the total synthesis of chiral 6-alkyl-δ-lactones, as exemplified by the preparation of both enantiomers of jasmine lactone ((6R)- and (6S)- 10 , resp.).     

Théorie quantique des phénomènes de biréfringence electrique et magnétique des molécules

A general formalism is set up to apply the variation-perturbation method to the quantum theory of non-linear optical effects, in particular to the electric and magnetic birefringence (Kerr and Cotton-Mouton effects). The quantities describing these effects are obtained from the wave function Ψ of the ground state of the unperturbed molecule and the different vectors and tensors which are determined by a variation method. With this method an approximate computation of the Kerr and Cotton-Mouton constants of some simple molecules has been made.     

Polymérisation et copolymérisation cationiques des methylindenes

A study of cationic polymerization and copolymerization of methylindenes has been carried out by experimental methods and by means of quantic chemistry. The study showed a great variation among initiators in efficiency for the various monomers. The study of the effect of temperature on polymerization was carried out for dimethyl-5,7-indene. Polymerization enthalpies and reactivity ratios were determined; the values that were obtained allowed a classification of methylindenes with regard to their reactivity toward a single cation. Total electron densities, free valences, and mobile bond orders, frontier electron densities, and superdelocalizabilities on position 1 and 2 were calculated for all methylindenes. In determining location energies of the electronic double bond in position 2 and the stabilization energies at the time of the attack by a cation, a theoretical classification of the monomers with respect to their reactivity in cationic polymerization was obtained. The agreement between calculation and experimental results is shown to be satisfactory.     

Synthèse et propriétés des aroylhydrazones du benzoate d'éthyle. Synthèses d'hétéroscycles azotes

The aroylhydrazones of ethyl benzoate have been prepared in fair yield by the action of aroylhydrazines on ethyl benzimidate hydrochloride. These products give rise, quantitatively, at their melting point, to 5-aryl-2-phenyl-1,3,4-oxadiazoles, and, in the presence of hydrazine hydrate, in boiling 1-propanol to 4-amino-5-aryl-3-phenyl(4H)-1,2,4-triazoles (Yields 50%). The addition of methylmagnesium iodide to these products give aroylhydrazones of acetophenone.     

Interactions Intramolécularies—XVII Calcul des constantes de couplage en RMN du cyclohexane et de cyclohexanes substitués. Comparaison des méthodes de Pople et Santry et des perturbations finies

Proton–proton ³J, ⁴J and ⁵J NMR coupling constants have been calculated for cyclohexane and monosubstituted cyclohexane conformers (substitiuents: Li, CH₃, OH, F) by the two methods mentioned. Comparing the two methods on the basis of group theory, we show the necessity to use the second. The results from this method are compared with those of the literature.     

La configuration du «carquéjol» (Isopropényl-2-méthylène-3-cyclohexène-4-ol) et la conformation privilégiée de l' ortho-néo-isomenthol

The complete stereochemistry of carquejol (= cis-(2S)-isopropenyl-3-methylene-cyclohex-4-en-1-ol) is described. The absolute configuration was obtained from the circular dichroism of the corresponding 0-menthones. Carquejol and its reduction products, having the all-cis configuration, appear from NMR. measurements to prefer a conformation having the hydroxyl (or acetoxyl) group axial and the isopropenyl (or isopropyl) group equatorial, even when the exo-methylene group is reduced to methyl. The mass spectra of the compounds are briefly described.     

Furannes et pyrroles disubstitues en 2,3. XVII. Structure des composés formés par eyanuration des halogénométhyl-2 méthoxycarbonyl-3 et −5 furannes

Treatment of methyl 2-bromomethylfuran-3-carboxylate with potassium cyanide yielded methyl 2-cyanomethylfuran-3-carboxylate, methyl 2-methyl-5-cyanofuran-3-carboxylate and two unusual products which appeared by nucleophilic substitution of the activated methylene group of the preceding furylacetonilrile. Products from the cyanide displacement reaction of methyl 5-chloromethylfuran-2-carboxylate are formed in the same way and their previously described formulas are corrected. On the other hand, it was pointed out that phosphorus oxychloride-pentachloride transformation of 2-cyanomethylfuran-3-carboxylic acid leads to 4,6-disubstituted furo[3,2-c]pyridines.     

Synthèse et réactivité des bromhydrines dérivées de la chromone

Bromohydroxylated derivatives of chromone are obtained by addition of N-bromosuccinimide in dimethylsulfoxide. The configuration and conformation of these compounds are confirmed by NMR spectroscopy. Alkaline alcoholates react with these bromohydrins to give a ring contraction into 2-formyl-3-benzofuranone.     

Etudes des sélénophènes mono et bisubstitués par Résonance Magnétique de 1H et de 13C

Proton and carbon magnetic resonance spectra of mono-and disubstituted selenophenes are investigated. The proton chemical shifts are discussed in terms of magnetic anisotropy and electric field effects of the substituents, with a view to studying the conformational equilibrium of the carbonyl group. π Electronic charges, computed by the PPP method, are correlated with the proton and carbon chemical shifts. The coupling constants between ¹³C and ¹H (1, 2 or 3 bonds) and ¹³C? ⁷⁷Se are shown to be good structural parameters and a set of substituent additivity constants is calculated.     

Etude par spectrométrie de masse des O-isopropylidène-1,2-thréo- et -érythro-furannoses et des quatre désoxy-5-O-isopropylidène-1,2-pentofurannoses

The mass spectra of the O-isopropylidene derivatives of threo- and erythro-furanose and those of the four C(4) methylated stereoisomers have been studied. Fragmentation modes based upon deuterium labelling, metastable peaks and high-resolution measurements are proposed. Each stereoisomer can be characterized by its low-resolution mass spectrum.     

Composés d'addition des halogénures de niobium(V) et de tantale(V). V. Stabilité relative des composés des chlorures avec quelques oxydes et sulfures organiques

The adducts of niobium(V) and tantalum(V) chlorides with some aliphatic and cyclic oxides and sulfides, studied by NMR. spectroscopy in CHCl₃, are found to have 1:1 stoechiometry, at room temperature and lower. In the thioxane complex TaCl₅ · C₄H₈OS two species are present with the ligand coordinated by the sulfur atom or by the oxygen atom, respectively, in a proportion which has been determined. The thioxane adduct of niobium(V) chloride, however, is preferentially coordinated by the sulfur atom. There is also evidence for the species 2MCl₅ · C₄H₈OS. The relative basicity of each donor atom in dioxane, thioxane and dithiane is calculated and discussed. In contrast to the nitrile adducts, whose stability was found earlier to be controlled by inductive factors, the steric factors are more important for the ether and sulfide adducts: MCl₅ · Me₂X is more stable than the corresponding MCl₅ · Et₂X (M = Nb, Ta; X = O, S). Both niobium(V) and tantalum(V) chlorides have a soft behaviour, but NbCl₅ is a weaker Lewis acid than TaCl₅ and shows also a softer behaviour.     

Synthèse partielle et propriétés oncostatiques des pseudo-tubulosines,analogues de l'émétine et de la tubulosine

Partial Synthesis and Oncostatic Properties of Pseudotubulosines, Analogues of Emetine and Tubulosine Pseudotubulosines, structural analogues of emetine and tubulosine, have been synthesized by either Pictet-Spengler or Bischler-Napieralski condensation from dihydrocorynantheal or corynantheidal. Spectral data, cytotoxic and oncostatic properties of these new alkaloids are described.     

Nature et stabilité des complexes métalliques de cryptands dinucléants en solution II. Polythiamacrotricycles et monocycles apparentés

Nature and Stability of Some Metallic Complexes of Dinucleating Cryptands in Solution II. Polythiamacrotricycles and Related Monocyclic Subunits The stability constants of the Cu²⁺ and Ag⁺ complexes of the cylindrical macrotricycle 1a (1,7,13,19-tetraaza 4,16-dioxa 10,22,27,32-tetrathiatricyclo[17.5.5.5]tetratriacontane) have been determined by pH-metry, as well as those of the Cu²⁺, Co²⁺, Zn²⁺, Cd²⁺, Pb²⁺, and Ag⁺ complexes of the monocyclic subunit 2a (1,7-dimethyl-1,7-diaza 4,10-dithiacyclododecane), in aqueous solutions (NaClO₄) at 25°. In the Cu(II) systems, equilibria were reached slowly, and the results established by pH-metry were confirmed by UV/VIS spectrophotometric studies. The tricycle 1a forms dinuclear cryptates with copper and silver, with overall stability constants log β₂₁₀ (Cu₂- 1a )⁴⁺ = 18.5, log β_21-2 (Cu₂- 1a (OH)₂)²⁺ = 4.8, log β₂₁₀(Ag₂- 1a )²⁺ = 23.0. Ag⁺ also forms a mononuclear (Ag- 1a )⁺ complex, with log β₁₁₀ = 13.1, but no mononuclear species were detected in the Cu- 1a system. The absorption spectra of the bis-Cu(II) complexes of 1a and 2a in aqueous medium, MeOH and propylene carbonate (PC) are given, as well as those, in MeOH and PC, of the bis-copper complexes of the related monocycles 3 and 4 (1,7-diaza-4,10,13-trithiacyclopentadecane and 1.10-diaza 4,7,13,16-tetrathiacyclooctadecane, respectively), and tricycle 5 with two benzyl groups in the lateral chains. The complexing properties of the polyoxa- and polythia macrotricycles (Parts I and II of this series) are compared to those of other bis-chelating ligands, the bicyclic bis-tren and the monocyclic bis-dien.