Piperidines 3-hydroxy

Die Reduktion von N-Hydroxy-piperidin zu Piperidin (82% d. Th.) in 0,2 m waBr. Oxalsaure ist als indi-rekte elektrolytischc Reduktion anzusehen, weil das gleichzeitig anwesendc Titan(IV)-chlorid bei -0,5 V zu Titan(III) reduziert wird, das dann scinerseits das Hydroxylamin reduziert. ... 

Sphingomonas sp. HXN-200 was also able to accept a six-member ring substrate. Hydroxylation of A/-benzyl- and A/-/ert-butoxycarbonyl-2-piperidinone gave the corresponding (/J)-4-hydroxy-piperidin-2-ones in 31% and 68% ee, respectively (Figure 15.4). This provides a simple synthesis of such types of useful synthons. 

In order to find the initiation rate, a set of polymerizations, in the presence of inhibitor (2,2,6,6-tetramethyl-4-hydroxy-piperidine-l-oxy), was carried out. Inhibition period was measured for polymerization with poly(dimethylmethacrylate), polyethylene glycol, or without any template. The results are presented on the Figure 8.10. The plot of concentration vs. inhibition time is a straight line — the same for all experimental points. It means that initiation rate is the same, independent of the presence of tern-... 

Allylische Silane gehen mit Benzylamin und waBrigem Formaldehyd in Gegenwart von Trifluoressigsaure eine Cyclokondensation ein unter Bildung von z. B. l-Benzyl-4-hydroxy-piperidin, 2-Renzyl-4a-hydroxy-cis-decahydro-isochinolin bzw. l-Benzyl-4-hydroxy-4-( 2-hydroxy-ethyl)-piperidin2. 

Chloro-phenyl)-4-hydroxy-piperidin-1-yl]-A/,/V-dimethyl-2,2-diphenyl-butyramide, 4-(4-chlorophenyl)-4-hydroxy-/V,/V-diemethyl-a,a-diphenyl-1 -piperidinebutanamide, C29H33CIN202, Mr 477.04 monohydrochloride [34552-83-5], C29H33CIN202 HCI, Mr 513.51, mp 222-223 °C (decomp.)... 

Carbamate 282, derived from (V-benzylpiperidine-2-methanol 281, undergoes stereoselective deprotonation when treated with. r-butyllithium and tetramethylethylenediamine to give lithiate 283, which can be trapped with numerous electrophiles to give, after hydrolysis of the carbamate, a single diastereoisomer of /(-hydroxy piperidines 284 (Scheme 67) <1999S1915>. 

Disubstituted piperidines (and piperideines) are well known as constituents of myrmicine ant venoms, particularly in fire ants of the genus Solenopsis (125,134,149,161,164). Both cis and trans isomers occur. Cis-and/or rrans-2-methyl-6-nonylpiperidines are prominent ant alkaloids. These ant alkaloids have not been detected in amphibians, but the 4-hydroxy piperidine analog (241D) has. 

Coupung, dehydrative Bis-o-phenylene pyrophosphite. N,N -Carbonyldiimidazole. N,N -Carbonyl-J-triazine. l-Cyclohexyl-3-(2-morpholinomethyl)-carbodiimide. 1,1-Di-chlorodiethyl ether. Dicyclohexylcarbodiimide. Diethyl chlorophosphonate. Diethyl-cyanamide. Diethyl ethylenepyrophosphite. N-(3-Dimethylaminopropyl)-N -ethylcarbo-diimide hydrochloride. Diphenylketene p-tolylamine. Ethoxyacetylene. l-Ethyl-3(3 -di-methylaminopropyllcarbodiimide hydrochloride. Ethylene chlorophosphite. N-Ethyl-S-phenyliioxazolium-3 -sulfonate. N-Hydropyridine. N-Hydroxyphthalimide. N-Hydroxy-piperidine, N-Hydroxysuccinimide. Phenylphosphorodi-d-imidazolate). 

Tab. 48 4-Hydroxy-piperidine durch Hydrierung substituierter 4-Oxo-piperidine1...

Oxo-piperidin Medium 4-Hydroxy-.. . -piperidin Gesamt- 4-Hydroxy- unver-... 

In the reduction of l-phenyl-3-hydroxypyridinium chloride considerable hydrogenolysis took place with the formation of 1-phenyl-piperidine (34%) along with 31% of the desired l-phenyl-3-hydroxy-piperidine (71). While Kao (72) reported very good yield of 3-hydrox-ypiperidine, Biel and his co-workers (73) found that piperidine (50% yield) was obtained in addition to 30-40% of 3-hydroxypiperidine. They postulate that an intermediate allyl type alcohol is formed which is more prone to hydrogenolysis than 3-hydroxypiperidine ... 

N-Hydroxy piperidine 0-(2,4-Dinitrophenyl)-hydroxylamine 0,N-Bis( trifluoro-acety I)hydroxy l-amine... 

IS -Hydroxy piperidine 0,N-Bis( trifluoroacetyl )-hydroxylamine Nitrogen oxides N2O, NO (nitric oxide), N2O3, NO2, N2O3 NH NOs... 

The 3-hydroxyquinuclidine esters also exerted a greater and more prolonged action upon the central nervous system than the esters of 2-diethylamino-etha-nol. In the course of investigating a group of iV-aIkyl-3-hydroxy-piperidine ben-zilates, Abood et al. [170], Lipman, Shurrager and Abood [179] noted that the compounds produced a marked and characteristic h5q>eractivity in rats which ac-... 

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