Spectres ir de quelques dérivés 3-acyl de la coumarine

The IR spectra of sixty-nine coumarin-3-acyl derivatives have been recorded and analysed in the region 4000-660 cm⁻¹ and 4000-400 cm⁻¹.

Band assignments are proposed as far as possible. Some absorption bands are characteristic for the examined coumarins and can be used in recognizing and differentiating a coumarin structure in an unknown compound.     

Synthèse de nouvelles amidines bicycliques . Dérivés de la pyrimidine,de la quinazoline et de la diazépine-1,3

The synthesis of pyrrolo[1,2-α] pyrimidines is described. Several homologous compounds contain pyridine or azepine instead of pyrrole ring. They are obtained by cyclization of iminolactams with β-ketoesters, αβ-unsaturated esters, aldehydes or ketones, or diketene. The possibility of obtaining isomers is discussed.     

Synthèse de dérivés de la benzo[c] quinolizine

The introduction of polar groups in planar polycyclic systems, for the purpose of studying their intercalating action, has been realized in the benzo[c]quinolizinium series. A functionalizing synthesis has been developed from 2-picolyl-and quinaldyllithium. Intermediate ketones or imines were cyclized by a quaternization reaction involving a concerted process. Structure and physico-chemical features of the compounds prepared were studied.     

Etude de la fragmentation par impact électronique de dérivés du benzothiazole

Study of Electron-Impact Fragmentation of Benzothiazole Derivatives The mass spectra of eighteen substituted benzothiazoles are reported and discussed. All these compounds are thermodynamically stable and give an intense molecular ion, which undergoes different types of fragmentation depending on the nature of the substituent which is rarely eliminated directly. β-Cleavage with respect to the heterocyclic double bond is often observed. Specific ²H-, ¹³C-, ¹⁵N- and ³⁴S-labelling have been used in order to confirm the fragmentation patterns.     

Dérivés de l'hydroxyméthyl-5 furfural. I. Synthése de dérivés du di- et terfuranne

Addition of α, β-unsaturated sulfones or ketones to 5-hydroxmethyl-furaldehyde or related furanaldehydes in the presence of a thiazolium salt gives di or tetraketonic furan compounds. Dehydrative cyclizationled to di- and terfuryl derivatives.     

Analogues azotés de dérivés de l'acide orotique

The synthesis of two new types of compounds with 3-oxo-5-thioxo- and 3,5-dithioxo-6-ethoxycarbonyl-2,3,4,5-tetrahydro-1,2,4-triazines are described. Their reactivity towards alkylating reagents and towards hydrazine has been studied.     

Dérivés C-glycosyliques XXIII. Radicaux libres stables dérivés de sucre Communication préliminaire

Treated with 2,3-dimethyl-2,3-bis-(hydroxylamino)-butane, aldehydo-dialdofuranoses ( 1 ) gave a mixture of two compounds: a 1,3-dihydroxyimidazolidine ( 2 ) and a 1-hydroxyimidazoline ( 3 ). Oxidation (PbO₂) of compounds 3 gave stable free radicals having the structure of 2-C-Glycosyl-4,4,5,5-tetramethylimidazolines 1-oxyl ( 4 ), whereas 2-C-Glycosyl-4,4,5,5-tetramethylimidazolines 3-oxide 1-oxyl ( 5 ) were formed by oxidation of 2 . The ESR. spectra of compounds 4 and 5 establish the structure of the imidazoline part of these radicals and provide informations on the sugar moiety.     

Application de la réaction de Wittig à la synthèse de dérivés de bromoénosuloses et d'esters bromoénuroniques. Note de laboratoire

Use of the Wittig reaction for the synthesis of derivatives of bromoenosuloses and bromoenuronic esters Treatment of 3-O-benzyl (or 3-O-methyl)-1, 2-O-isopropylidene-α-D -xylo-pentodialdo-1, 4-furanoses ( 2 or 1 ) with acetylbromomethylidenetriphenylphosphorane ( 3 ), benzoylbromomethylidenetriphenylphosphorane ( 4 ) or bromoethoxycarbonylmethylidenetriphenylphosphorane ( 5 ) gave in good to excellent yields the expected enose ( 6--11 ). In all cases but one ( 8 where some 10% of the E-isomer was formed) the reaction led to the exclusive formation of the Z-isomer whose configuration was established by NMR.     

Sur les dérivés de la fluorénone VII. Bifluorényles et bifluorénonyles

Starting from 3-bromo-, 1-iodo- and 4-iodo-9-oxo-fluorene three symmetrical bifluorenonyls and the corresponding hydrocarbons 3,3′-, 1,1′- and 4,4′-bifluorenyls are prepared. An attempt to obtain the non-symmetrical 1,2′-bifluorenyl is also described.     

Préparation de la 8,14-diméthyl 18-nor-testostérone

Les sécrétions de 4 espèces de Dipterocarpus Viêt-Namiens ont fourni un triterpène tétracyclique, identifié au diptérocarpol de van Itallie et à l'hydroxy-dammarénone-II (I) de Mills. Le diptérocarpol est dégradé (chaîne latérale) et modifié (cycle A) en un analogue de la testostérone (XXX). Sa stéréochimie est discutée.     

Radicaux libres dérivés de sucres. V. Dérivés d'osamines N-hydroxylées et composés voisins Communication préliminaire

Free sugar radicals. V. Deoxyhydroxylaminosugar derivatives and related compounds We describe several synthetic routes to deoxyhydroxylaminosugar derivatives of the type Glyc-N(OH)-R where Glyc stands for a sugar moiety linked by any of its C-atoms except the anomeric one and R for one of the following substituants: H-atom, acyl, phosphoryl groups, aminoacid or sugar residues. Compounds of the above structure are potentially close analogs, homoisosteres, ? NOH? replacing ? O? , of biochemically important molecules. Under aerobic conditions, solutions of these derivatives contain minute concentrations of the corresponding nitroxide radicals which do not decrease significantly the resolution of the NMR. spectra but render these compounds usable as a new kind of spin labels. Spectroscopic properties (¹H-NMR., ¹³C-NMR., ESR.) of some of these compounds are reported.     

Régiospécificité de la cycloaddition des diarylnitrilimines sur quelques dérivés indoliques

In this paper, we describe the results of a study of the reaction of diaryl nitrilimines with N-ethylindole ( 1 ) and 2-methoxycarbonyl-N-ethylindole ( 2 ). The regioselectiivity of the reaction is reversed when going from 1 to 2 as it has been spectroscopically and chemically demonstrated.     

Dérivés de sucres benzimidazoliques et benzothiazoliques

Benzimidazole and benzothiazole sugar derivatives Simple aldehydosugars such as 1 or 2 , by reaction with o-phenylenediamine, gave the corresponding benzimidazoles 3 and 4 . Whereas the unperturbed α, β-unsaturated aldehydosugar D gave the benzodiazepine E upon treatment with o-phenylenediamine, the formyl-bearing alkenyl acetals 5 and 8 led, in the same conditions, to the benzimidazoles 6 and 9 respectively or, on reaction with o-aminothiophenol, to the benzothiazoles 7 and 10 respectively. This difference in reactivity is explained by the electrondonor ability of the oxygen atom of the alkenyl acetal function as shown by the ¹³C-RMN. spectra.     

Dérivés C-glycosyliques. VII. Synthèse et réactions de nitrones dérivées de sucres. Communication préliminaire

The syntheses of three types of sugar nitrones (aldonitrone, ketonitrone and α-β unsaturated aldonitrone) are described. On 1,3-dipolar cycloaddition with phenylacetylene, the aldonitrone gave two Δ₄-isoxazolines epimeric at the new asymetric carbon, while the same reaction on the ketonitrone led to a spiro-Δ₄-isoxazoline. The reaction of these nitrones with carbon nucleophiles like phenylethynylmagnesium bromide constitutes a novel chain-extension reaction in carbohydrate chemistry.