Darstellung von 1.3‐Dioxolanen aus Aldehyden und Epoxiden in neutralem Medium

Nerdel, Friedrich; Buddrus, Joachim; Scherowsky, G.; Klamann, Dieter; Fligge, Manfred

doi:10.1002/jlac.19677100110

Cited by 21 publications

(10 citation statements)

References 8 publications

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“…108 Heating 1-chloro-2,3-epoxypropane (169) with R F -nitriles at 150 o C in a glass-pressure tube in the presence of tetraethylammonium bromide as the catalyst led to the formation of the corresponding R F -oxazolines 172-174 in moderate yields. 109 The suggested plausible mechanism involves the nucleophilic addition of intermediate 1-bromo-3-chloropropan-2-ol (170) to the activated cyano group of R F CN and subsequent cyclization of anion 171 to give 172-174 (Scheme 87). 109 Scheme 87.…”

Section: Reactions With Nucleophiles 331 Reactions With O-nucleophilesmentioning

confidence: 99%

“…109 The suggested plausible mechanism involves the nucleophilic addition of intermediate 1-bromo-3-chloropropan-2-ol (170) to the activated cyano group of R F CN and subsequent cyclization of anion 171 to give 172-174 (Scheme 87). 109 Scheme 87. Reaction of 1-chloro-2,3-epoxypropane (169) with R F -nitriles.…”

Section: Reactions With Nucleophiles 331 Reactions With O-nucleophilesmentioning

confidence: 99%

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Chemistry of fluoroalkyl cyanides

Usachev¹

2020

Arkivoc

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This review is devoted to the chemistry of fluoroalkyl cyanides (R F -nitriles): their synthesis and chemical properties. Syntheses of non-functionalized R F -nitriles (FCH 2 CN, F 2 CHCN, CF 3 CN, C 2 F 5 CN, FCH 2 CH 2 CN, etc.) and dinitriles (NCCHFCN, NCCF 2 CN, NCCF 2 CF 2 CN, etc.) are considered. The synthesis of functionalized R F -nitriles such as F 2 NCF 2 CN, F 2 NCClFCN, Cl 2 CFCN, Br 2 CFCN, (O 2 N) 2 CFCN, O 2 NCF 2 CH 2 CH 2 CN, and dinitriles, such as O(CF 2 CN) 2 , NCCF 2 N=NCF 2 CN, is also considered. R F -Nitriles are attractive electrophilic, enophilic, and dienophilic building-blocks: they were used in the synthesis of various fluorine-containing heterocyclic compounds, such as R F -bearing pyridines, 1,3,5-triazines, tetrazoles, and others. R F -nitriles were also used in the synthesis of unusual acyclic compounds, such as fluoroalkylated N,N-difluoroamines, F 2 NCF 2 CF 2 N=SF 2 , R Fimino esters, and others.

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Section: Reactions With Nucleophiles 331 Reactions With O-nucleophilesmentioning

confidence: 99%

Section: Reactions With Nucleophiles 331 Reactions With O-nucleophilesmentioning

confidence: 99%

Chemistry of fluoroalkyl cyanides

Usachev¹

2020

Arkivoc

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“…-Bei der Umsetzung des Piperidinderivates 10 mit dem Homer-Wittig-Reagens 17 wurde in 79% Ausbeute der Trimethylester 19 erhalten, der durch die oben erwahnte modifizierte PJitzner-Mo~ut-Oxydation [8] in ein (45 : 55)-Gemisch der (2) Aus der Reaktion des N-Formylpiperidin-Derivates 27 mit Bromessigsaureathylester (34) und Triphenylphosphin (35) in Gegenwart von Athylenoxid nach Buddrus [18] wurde nicht 28, sondern 64% des Acetals 36 isoliert. Offenbar katalysiert ein Phosphoniumsalz die Acetalisierung der Carbonylgruppe durch Athylenoxid, wie dies auch fur Ammoniumsalze bekannt ist [19]. [20] bei Versuchen zur Dehydratisierung der Reformatsky-Produkte aus verschiedenen ,!…”

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Totalsynthese von Betalainen

Hermann

1977

Helvetica Chimica Acta

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Total Synthesis of BetalainesSummary cis-4-0~0-2,6-piperidinedicarboxylic acid dimethyl ester (10) was transformed (44%) into the semicarbazone of 2,3-dihydrobetalamic acid dimethyl ester (13/14) by a modified Horner-W i t t i g reagent 12. Oxidation of 13/14 afforded 41 YO of a mixture of stereoisomers of betalamic-acid-dimethyl-ester semicarbazone (4), key intermediate for the synthesis of betalaine pigments. The utility of 4 in this respect was demonstrated on a small scale by its conversion to the dimethyl ester of indicaxanthine (9, 11%) and to the trimethyl ester of betanidine (7, 87%). Hydrolysis of 7 gave betanidine (6).We further describe the synthesis of the trimethyl ester of an oxidized form of betalamic acid (20/21) as well as model condensation reactions on the carbonyl group of cyclohexanone, cis-4-0~0-2,6-diphenylpiperidine (23) and its N-formyl derivative 27.Reaction of 4-0x0-1,2,3,4-tetrahydro-2,6-pyridinedicarboxylic-acid dimethyl ester (40) with acetic anhydride or with triethyloxonium tetrafluoroborate resulted in 0-acylation or in 0-alkylation along with dehydrogenative aromatization to yield the derivatives 39 or 42, respectively, of chelidamic acid.

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“…C80,34 H7,16 N5,860/: Gef. C79,98 117,74 N5,58y0 XV: C1,H,,NO (255,4) ,, ,, 80,Ol ,, 8,29 ,,5,48o/b Vf: C1,H1,NO,(257,3) ,,,,74,67 ,,7,46 ,,5,447h Die Analyse spricht cbcnso wic die Diinnschichtchromatographie fur die Uneinheitlichkeit des Praparates. Dic Anwcscnhcit eines betrachtlichcn Antcils von Vf (Wasseranlagerungsprodukt von XIII) ist auf Grunci des niedrigen C-Gehaltes von Vf auszuschlicsscn.…”

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“…2-Methyl-4-liexyl-1,3-dioxolan (VI) wird entweder durch die von quartaren Aminoniumsalzen katalysierte Reaktion [3] zwischen Acetaldehyd (insofern vorlianden) und 1,Z-Epoxyoctan oder aus den1 quartaren Salz V b nach den1 untcn angegebenen Mcchanismus gebildet. V selbst (als V a oder Vb) entsteht durch die Einwirkung von Epoxid auf IIa (Reaktionsweg (5)) oder auf I I I a (Reaktionsweg (4)).…”

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Die Reaktion von 1,2‐Epoxy‐octan mit 2‐Dimethylamino‐äthanol

Tobler¹

1969

Helvetica Chimica Acta

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2‐Dimethylaminoethanol reacts with 1,2‐epoxyoctane presumably via a hydrogen‐bonded complex to form a quaternary ammonium compound which exhibits a fair stability at lower temperatures. At higher temperatures the quaternary structure decomposes with the resulting formation of a wide variety of products. Most of the products have been identified and a reasonable mechanistic picture for their formation is presented. The main products of the reaction are 1‐(ß‐dimethylaminoethoxy)‐2‐octanol (IIIa) and 1‐dimethylamino‐2‐octanol (IV), the latter being formed according to several pathways concurrently with ethylene oxide, 2‐methyl‐4‐hexyl‐1, 3‐dioxolane (VI), and 2‐hexyl‐1, 4‐dioxane (VII). Some of the higher molecular weight products are secondary products resulting from the action of epoxide on the primary reaction products IIIa and IV. The relative amount of each product formed depends on the ratio of starting materials and reaction temperature. In the presence of an additional hydroxylic solvent such as ethanol, the solvent enters also into the reaction.

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Darstellung von 1.3‐Dioxolanen aus Aldehyden und Epoxiden in neutralem Medium

Abstract: Aromatische und in a-Stellung substituierte, aliphatische Aldehyde reagieren mit Epoxiden in Gegenwart eines neutralen Katalysators in guten Ausbeuten zu 1.3-Dioxolanen. In a-Stellung unsubstituierte Aldehyde geben daneben noch Aldolreaktion.

Cited by 21 publications

References 8 publications

Chemistry of fluoroalkyl cyanides

Chemistry of fluoroalkyl cyanides

Totalsynthese von Betalainen

Die Reaktion von 1,2‐Epoxy‐octan mit 2‐Dimethylamino‐äthanol

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