## Abstract A number of hydroxytelechelic polybutadiene samples were silylated. The completeness of the silylation reaction allows the determination of the number average functionality by continuous wave ^1^H NMR. The protonated groups of the silylated alcohol functions were identified at 100 and 2
Synthèse de polybutadiènes nitrés hydroxytéléchéliques par nitromercuration-demercuration—I. Étude de la réaction de nitromercuration
✍ Scribed by F. Lugadet; A. Deffieux; C. Servens; M. Fontanille
- Publisher
- Elsevier Science
- Year
- 1989
- Tongue
- English
- Weight
- 490 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0014-3057
No coin nor oath required. For personal study only.
✦ Synopsis
R6sum6---Parmi les diff~rentes m&hodes de nitration des polybutadi6nes, celle qui utilise la nitromercuration par [HgCl2, NaNO2] est int6ressante d plusieurs points de vue. Dans un premier article, la r6action de nitromercuration est plus particuli6rement examin6e. Les conditions permettant de limiter l'influence d'une r6action de chloromercuration des chaines ainsi que la cause de l'insolubilisation partielle des polym6res au cours de la transformation ont 6t6 recherch6es. Cette derni~re est &roitement li6e au taux de mercure fix6 sur les chaines. La nitromercuration des deux types d'insaturations (1,2 et 1,4) s'effectue sans s61ectivit6 marqu6e. Enfin, les proportions relatives de groupements nitro et nitrite fix6s sur le polym6re selon les conditions de la r6action ont 6t6 examin6es. L'addition de d6riv6s ph6noliques au milieu r6actionnel permet d'accroitre la s61ectivit~ en groupes nitro.
📜 SIMILAR VOLUMES
## Abstract The examination, by ^1^H NMR, of anionic hydroxytelechelic polybutadienes in conjunction with accurately measured M~n~ values allows the simultaneous determination of the number average functionality and the identification of the nature of the chain ends bearing the functional groups. T
## Abstract The orientation of the cycloaddition of diazomethane on unsaturated branchedchain sugars has been studied. For 3‐__C__‐cyanomethylidene‐3‐deoxy‐1,2‐__O__‐isopropylidene‐α‐D‐__glycero__‐tetrofuranose the orientation was ‘normal’ and did not depend on the configuration at the double bond.
## CONTRIBUTION A L'ETUDE DES REACTIONS DE PECHMANN ET SIMONIS A. RUWET, D. JANNE et M. RENSON The Pechmann and Simonis reactions are investigated with phenols (0, S, Se). Thio and selenophenols give thio-1 and seleno-1 chromones (Simonis reaction). Several cyclizing agents are studied. Ethyl ace