scholarly journals Microwave-assisted regioselective ring opening of non-activated aziridines by lithium aluminium hydride

2010 ◽  
Vol 8 (19) ◽  
pp. 4266 ◽  
Author(s):  
Sonja Stanković ◽  
Matthias D'hooghe ◽  
Norbert De Kimpe
Keyword(s):  
Ring Opening ◽  
Lithium Aluminium Hydride ◽  
Microwave Assisted ◽  
Lithium Aluminium

Competing Radical- and Anion-Mediated Pathways in the Reduction of Bridgehead Tosylates with Lithium Aluminium Hydride

1999 ◽  
Vol 52 (5) ◽  
pp. 367 ◽  
Author(s):  
Ernest W. Della ◽  
Wit K. Janowski
Keyword(s):  
Electron Transfer ◽  
Ring Opening ◽  
Radical Anion ◽  
Lithium Aluminium Hydride ◽  
Trans Isomers ◽  
Lithium Aluminium ◽  
Mechanism Of Reaction ◽  
Anion Transfer

Reaction of norborn-1-yl tosylate with lithium aluminium hydride in boiling tetrahydrofuran affords a mixture of norbornan-1-ol accompanied by the ring-opened products 4-methylcyclohexanol and 3-ethylcyclopentanol as their cis/trans isomers, as well as p-thiocresol and p-tolyl disulfide. Evidence strongly suggests that the reaction is mediated by the norborn-1-yloxy radical rather than the norborn-1-yloxy anion. The process is initiated by very slow acyl oxygen fission of the norbornyl tosylate, followed by reduction of the derived p-toluenesulfinate ion to give the p-thiocresoxide anion. Transfer of an electron from the latter to the substrate and decomposition of the derived norborn-1-yl tosylate radical anion leads to the norborn-1-yloxy radical which, upon ring opening, generates the monocyclic alcohols via the corresponding ketones. It is noteworthy that, when norborn-1-yl mesylate is exposed to lithium aluminium hydride, it yields norbornan-1-ol exclusively. In the absence of an efficient electron-transfer agent, the mechanism of reaction of norborn-1-yl mesylate is suggested to involve acyl oxygen fission only.

Influence des groupes tert-butyle, triméthylsilyle et triméthylgermyle sur la stéréochimie de réactions d'addition en série cyclohexénique. II. Epoxydation des dérivés vinyliques et ouverture des époxydes par LiAlH4, MeOH/H+ et H2O/H+

1978 ◽  
Vol 56 (15) ◽  
pp. 2049-2052 ◽  
Author(s):  
Jean-Claude Richer ◽  
Marc-André Poirier ◽  
Yvette Maroni ◽  
Georges Manuel
Keyword(s):  
Ring Opening ◽  
Acidic Medium ◽  
Lithium Aluminium Hydride ◽  
Electronic Effects ◽  
Tert Butyl ◽  
Lithium Aluminium

Epoxidation of 1-tert-butyl (1a), 1-trimethylsilyl (1b), and 1-trimethylgermyl (1c) 4,4-dimethylcyclohexenes is described and the stereochemistry of the ring opening of the resulting epoxides (3a, 3b, 3c) by lithium aluminium hydride as well as methanol and water in acidic medium is examined. The regiochemistry of the ring opening of 3a is completely reversed, in the case of 3b and 3c, by the electronic effects of the trimethylsilyl and trimethylgermyl groups.

Convenient Synthesis of (Z)-7- and (E)-9-dodecene-1-yl Acetate, Components of Some Lepidoptera Insect Sex Pheromone

2017 ◽  
Vol 68 (1) ◽  
pp. 180-185
Author(s):  
Adriana Maria Andreica ◽  
Lucia Gansca ◽  
Irina Ciotlaus ◽  
Ioan Oprean
Keyword(s):  
Sex Pheromone ◽  
Coupling Reaction ◽  
Coupling Scheme ◽  
Lithium Aluminium Hydride ◽  
Terminal Alkyne ◽  
Mercury Derivative ◽  
Lithium Aluminium ◽  
Convenient Synthesis ◽  
Practical Synthesis ◽  
Insect Sex

Were developed new and practical synthesis of (Z)-7-dodecene-1-yl acetate and (E)-9-dodecene-1-yl acetate. The routes involve, as the key step, the use of the mercury derivative of the terminal-alkyne w-functionalised as intermediate. The synthesis of (Z)-7-dodecene-1-yl acetate was based on a C6+C2=C8 and C8+C4=C12 coupling scheme, starting from 1,6-hexane-diol. The first coupling reaction took place between 1-tert-butoxy-6-bromo-hexane and lithium acetylide-ethylendiamine complex obtaining 1-tert-butoxy-oct-7-yne, which is transformed in di[tert-butoxy-oct-7-yne]mercury. The mercury derivative was directly lithiated and then alkylated with 1-bromobutane obtaining 1-tert-butoxy-dodec-7-yne. After acetylation and reduction with lithium aluminium hydride of 7-dodecyne-1-yl acetate gave (Z)-7-dodecene-1-yl acetate with 96 % purity. The synthesis of (E)-9-dodecene-1-yl acetate was based on a C8+C2=C10 and C10+C2=C12 coupling scheme, starting from 1,8-octane-diol. The first coupling reaction took place between 1-tert-butoxy-8-bromo-octane and lithium acetylide-ethylendiamine complex obtaining 1-tert-butoxy-dec-9-yne, which is transformed in di[tert-butoxy-dec-9-yne]mercury. The mercury derivative was directly lithiated and then alkylated with 1-bromoethane obtaining 1-tert-butoxy-dodec-9-yne. After reduction with lithium aluminium hydride of 1-tert-butoxy-(E)-9-dodecene and acetylation was obtained (E)-9-dodecene-1-yl acetate with 97 % purity.

3-(s-Hydrindacen-4-yl)propylamines and 4-(s-hydrindacen-4-yl)butylamines; Synthesis and pharmacological screening

1981 ◽  
Vol 46 (8) ◽  
pp. 1800-1807 ◽  
Author(s):  
Zdeněk Vejdělek ◽  
Marie Bartošová ◽  
Miroslav Protiva
Keyword(s):  
Malonic Acid ◽  
Local Anaesthetics ◽  
Lithium Aluminium Hydride ◽  
Spasmolytic Activity ◽  
Lithium Aluminium ◽  
Malonic Acid Derivatives ◽  
Pharmacological Screening ◽  
Hydroxyethyl Piperazine

4-Chloromethyl-s-hydrindacene (VIIa) was transformed via the malonic acid derivatives VIIIa and IXa to the acid Xb which afforded in four steps the homological acid Xc. Reactions of chlorides of both acids (XIbc ) with dimethylamine, 1-methylpiperazine and 1-(2-hydroxyethyl)piperazine led to the amides XIIbc-XIVbc which were reduced with lithium aluminium hydride to the title compounds IVcd-VIcd. The amines obtained show central neuroleptic effects only in subtoxic doses; they are also potent local anaesthetics and have significant spasmolytic activity of the neurotropic as well as musculotropic type.

Substituted N,N-Dimethyl-3-(phenylthio)- and -4-(phenylthio)benzylamines

1992 ◽  
Vol 57 (1) ◽  
pp. 194-203 ◽  
Author(s):  
Karel Šindelář ◽  
Vojtěch Kmoníček ◽  
Marta Hrubantová ◽  
Zdeněk Polívka
Keyword(s):  
Serotonin Receptors ◽  
Hydrobromic Acid ◽  
Antidepressant Activity ◽  
Benzoic Acids ◽  
Lithium Aluminium Hydride ◽  
Acid Chlorides ◽  
Activity Inhibition ◽  
Lithium Aluminium ◽  
The Brain

(Arylthio)benzoic acids IIa - IIe and VIb - VId were transformed via the acid chlorides to the N,N-dimethylamides which were reduced either with diborane "in situ" or with lithium aluminium hydride to N,N-dimethyl-(arylthio)benzylamines Ia - Ie and Vb - Vd. Leuckart reaction of the aldehydes IX and X with dimethylformamide and formic acid afforded directly the amines Va and Ve. Demethylation of the methoxy compounds Ia and Ve with hydrobromic acid resulted in the phenolic amines If and Vf. The most interesting N,N-dimethyl-4-(phenylthio)benzylamine (Va) hydrochloride showed affinity to cholinergic and 5-HT2 serotonin receptors in the rat brain and some properties considered indicative of antidepressant activity (inhibition of serotonin re-uptake in the brain and potentiation of yohimbine toxicity in mice).

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