L-Alkyl-2-hydroxy

Die katalytische Hydrierung von N-Ethoxycarbonyl-2-nitro-anilinen liefert o-Diamino-arene ( 100%), die sich thermisch zu l-Alkyl-2-hydroxy-benzimidazolencyclisieren lassen590. 

The importance of ring size holds also for tautomerism of -pyrrol-5-ones and. d -dihydro-6-pyridones. While the former compounds behave as cyclic 1-methyl-2-alkyl-2-hydroxy-5-pyrrolidones 179) (76) [or, on distillation, as the dehydrated l-methyl-2-alkyl-J -pyrrolones (77)], the latter compounds exist as acyclic N-methylamides of 8-oxo-acids (78) [as shown by infrared spectroscopy (/80)j. The dehydration of 78 during distillation to form l-methyl-2-alkyl-. -dihydro-6-pyridones (79) is achieved only with difficulty. 

Asymmetric alkylation of a-substituted benzyl cyanides has been achieved using A-benzylquininium and cinchonium salts using procedures analogous to those described in 6.2.2 [19, 20], Analogous reactions catalysed by l-alkyl-3-hydroxy-quinuclidinium salts are less effective than those catalysed by quininium salts [20], whereas 1 -methyl-1 -diphenylmethyleneimino-2(5)-hydroxymethylpyrroli-dinium iodide is a more effective catalyst (>70% ee) [18]. 

Mit primaren Aminen statt Ammoniak werden aus 2,3,4,5-Tetraphenyl- oder 3,4,5-Triphenyl-1,3-oxazolium-Salzen l-Alkyl-2,3,4,5-tetraphenyl- bzw. l-Alkyl-3,4,5-triphenyl-imidazolium-Salze erhalten. In den meisten Fallen konnen die als Zwischenprodukte auf-tretenden l-Alkyl-4-hydroxy-3,4,5-triphenyl-4,5-dihydro-imidazolium-Salze isoliert werden344. 

Oxo-2,3-dihydro-l,3-oxazole konnen mit Isocyanaten in Ausbeuten von 80-90% zu Harn-stoff-Derivaten umgesetzt werden. Diese lagem sich saurekatalysiert in Ausbeuten von 44-97% (meistens iiber 90%) in die entsprechenden 1-Alkyl-2-hydroxy-imidazole um388 ... 

Die Metallierung von N -Alkyl-N.N-dimethyl-formamidinen mit tert.-Butyl-lithium, ge-folgt von der Umsetzung mit Aldehyden oder Ketonen und Hydrolyse des nicht isolierten Zwischenproduktes ergibt l-Methylamino-2-hydroxy-alkane1 ... 

Kontoghiorghes, G.J. and Sheppard, L., Simple synthesis of the potent iron chelators l-alkyl-3-hydroxy-2-... 

Heterocyclic coupling components that have been coupled with diazotized ami-nophenyltrimethylammonium chloride are l-alkyl-6-hydroxy-2-pyridone [93], 1-amino-3-hydroxy-isoquinoline [94], and 2,4-diamino-6-hydroxypyrimidine [95], The trialkylammoniumaryl residue may also be connected to the aromatic diazo component via a sulfone or a sulfonamido function [96], Disazo dyes in this series (e.g., 34) [77901-21-4] may also be generated from monoazo dyes that still contain a primary amino group by dimerization using phosgene [97] or cyanuric chloride [98],... 

An enantioselective aryloxylation of aldehydes is based on their prior conversion to an enamine through reaction with a chiral secondary amine catalyst. A subsequent inverse HDA reaction with o-quinones leads to 3-alkyl-2-hydroxy-l,4-benzodioxins with ee ca. 80% (Scheme 47). Manipulation allows the synthesis of (S)-2-alkyl-2,3-dihydro-l,4-benzodioxins <07TL1605>. In like manner, racemic nitidanin, which possesses antimalarial properties, has been synthesised through a regioselective cycloaddition of an o-quinone with a protected 3-arylpropen-l-ol <07TL771>. 

Treatment of an (allyloxymethyl)cyclopropane derivative with butyllithium also resulted in alkylation accompanied by C-O bond cleavage,but other products predominated to a considerable extent, rendering the method synthetically useless. Another and more successful rearrangement took place on refluxing 4-(l-cyclopropylalkoxy)-5-methoxy-l,2-benzoquinones in acetic acid to give 3-alkyl-2-hydroxy-5-methoxy-l,4-benzoquinone in 25-40% yield. 

Z)-l-Hydroxy-2,5-aIkadiene reagieren bei 260° unter 1,5-Homodicnyl-Wasscrstoff-Verschiebung iiber die Enole zu cis- l-Alkyl-2-formylmethyl-cycIopropanen110 ... 

Pharmaceutical creosote preparations are derived from the processing of such woody plants as beechwood (von Burg and Stout 1992). Wood creosote (beechwood creosote) is a yellow, transparent liquid with a characteristic smoky odor, obtained by fractional distillation of wood tar. It is composed primarily of phenol, phenols, cresols, guaiacols, xylenols, and small amounts of alkyl-2-hydroxy-2-cyclopenten-l-ones. It has been used as an expectorant, a gastric sedative, a gastrointestinal antiseptic, and particularly as an antidiarrheal agent (Ogata et al. 1993). Wood creosote and coal tar creosote are chemically distinct, and should not be confused with one another (see Chapter 4). 

Sato K., Inoue S. and Ohashi M. (1974) New synthesis of 3-alkyl-2-hydroxy-2-cyclohexen-l-ones. Bull. Chem. Soc. Jpn 47, 2519-22. 

S)-l-Benzyloxycarbonyl-2-[hydroxy(diphenyl)methyl]pyrrolidine [(S)-25] was used as an auxiliary in the enantioselective reduction of carbonyl compounds to secondary alcohols (Section D.2.3.2.) it is prepared analogously to the a,a-dimethyl derivative25. The A -methyl derivative (S)-26 (DPMPM) is among the most selective catalysts for the addition of zinc alkyls to carbonyl compounds (Section D.1.3.1.4.). 

Carmella, S.G., S.S.Hecht, andD.Hoffmann Quantitative analysis of alkyl-2-hydroxy-2-cyclopenten-l-ones in tobacco smoke 33rd Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 33, Paper No. 54, 1979, p. 29. 

Fragmentation processes of photoinitiators form a number of volatile products, which may contribute to indoor air pollution. Benzaldehyde and alkyl-substituted benzalde-hydes are usual components, because Norrish-I is the most important reaction for cleavage. Awell known example is l-phenyl-2-hydroxy-2-methyl-propane-l-one (PHMP). a-Cleavage generates two radicals in the first step. The benzoyl radical may recombine to form benzil, reduction of PHMP leads to l-phenyl-2-methy 1-1,2-propane and acetone, and recombination of the 2-hydroxypropyl radical gives 2,3-dimethyl-2,3-butanediol... 

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