Proline piperidine derivative from

The deprotection of aloe derivatives of secondary amines such as N,N-benzylme-thylamine under the above conditions gave a substantial amount of the undesired allylamine [32], However, the use of a 40-fold excess of diethylamine as the jr-allyl scavenger led to the desired benzylmethylamine in quite good yield (Eq. 9). The formation of the undesired allylamine was also suppressed using a fivefold excess of diethylamine in a butyronitrile/water system. N-Allyloxycarbamates derived from secondary amines, such as morpholine, piperidine, proline, and ephedrine, reacted under the above-mentioned conditions at room temperature within 15 min to give the parent amines in quantitative yields without formation of the undesired allylamine. 

The selection of successful N-mono-oxides also includes 21.27 (QUINOX, < 98 2 er at 5 mol% loading at -40 °C in dichloromethane) and para-cyclophane 21.28 (<98 2 er at 1.5 mol% loading at -40°C in acetonitrile). Hoveyda and Snapper reported on the first nonpyridine-type iV-mono-oxide 21.29 derived from proline (<96 4 er at 10 mol% loading at RT in CH2ClCH2Cl), which later was complimented by piperidine and tetrahydroquinoline analogues. Other pyridine-type N-oxides... 

There is continued interest in chiral syntheses of pyrrolidines, piperidines, and related bicyclic systems. A review has appeared, in Russian, on the stereoselective synthesis of proline and pipecolic acid derivatives from sugars. The antifungal pyrrolidine (+)-preussin (74) has been made from the glucose-derived epoxide (73) as indicated in Scheme 16,58 whilst... 

By surveying 72 catalysts from the proline family, including piperidine- and pyrrolidine-derived catalysts, amino acids and diamines investigated over the past decade (Appendices 7.B-D), we may better understand both the structural features that are compatible with a successful catalyst and those which are detrimental and preferably avoided. 

The only enantioselective synthesis of julandine to date is due to Kibayashi and co-workers (593). Lewis acid-catalyzed condenseition between silyl enol ether 901 and the acyliminium ion formed from the proline-derived lactam 902 was highly diastereoselective (>99% de), giving a 76% yield of the piperidin-2-one 903 (Scheme... 

Work in the group of Speckamp has shown that C-Cl bonds in a captodative position are weak enough to lead to radical chain cyclization reactions by chlorine atom transfer [28], Chlorine atom transfer from 34 to the catalyst, Cu Cl-bipyridine, leads to radical 35 which then undergoes 5-exo intramolecular addition to form the proline derivative 36 (Eq. 1). The captodative substitution is necessary for this radical process in the absence of an electron-withdrawing substituent, a cationic reaction leading to a piperidine occurs instead [29]. 

From the aspect of chemical carcinogenity the polarographic determination of N-nitrosamines become important. These compounds may be present in food, beverages and atmosphere, occasionally they can be formed in the body by nitrosation of amines, especially in the stomach. There were many papers published describing the determination of various nitrosamines (derivatives of proline, pyrolidine, piperidine, etc.) in different matrices[26]. The most important problem in their analysis (as with the... 

Method Four, Fischer and Zempl n (313, 314). Piperidine N-ben-zoylpiperidine 8-benzpylvaleric acid a-bromo-8-benzoylamino-valeric acid -> o-amino-8-benzoylaminovaleric acid -> proline. The synthesis through the corresponding m-nitrobenzoyl derivatives was described by Fischer and Zempl (314). The preparation of o-bromo-8-benzoylaminovaleric acid (A) from cyclopentanone oxime throu the intermediates a-piperidone, 8-aminovaleric acid and 8-benzoylamino-vaieric acid has been reported by Schniq >p and Marvel (688). Mayeda and Nozoe (564) sjmthemzed (A) essentially by the method of Schniepp and Marvel. Copper prolinate dibydrate was prepared from (A). 

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