4’-Alkyl-4-hydroxy

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 Solvolyse der Enaminel liefert 1-Alkyl-2-hydroxy-benzimidazole, die tautomer als 2-Oxo-2,3-dihydro-benzimidazole vorliegen597. 

Kalaitzakis, D., Rozzell, J.D., Kambourakis, S. and Smonou, I., Synthesis of valuable chiral intermediates by isolated ketoreductases application in the s3mthesis of -alkyl—hydroxy ketones and 1,3-diols. Adv. Synth. Catal, 2006, 348, 1958-1969. 

Photochemical a-hydroxyalkylation by alcohols is strictly connected with photochemical alkylation. With quinoline an acidic medium leads to alkylation hydroxy alkylation takes place with nonprotonated bases. The suggested mechanism is substantially identical for both processes. A IT -> 7T excited state would cause the initial hydrogen abstraction (Scheme 11). 

In alkaline solution, 0-alkyl hydroxy oxadiazoles are transformed into hydroxy derivatives while the action of amines yields amino-oxa-diazoles. 

When the lithium dianion was prepared in a completely different manner, viz from an a,j -epoxy ester 8 by treatment of the latter with lithium in liquid ammonia and tetrahydrofuran at - 78 C, alkylation experiments (CH3I, — 40 °C) gave the expected a-alkyl- -hydroxy ester 10, but in a ratio of only 4 1 in favor of the anti-isomer and not in the usual 19 1 ratio15. This result could be interpreted as a direct consequence of the participation of an intermolecularly chelated dianionic enolate such as 7 which gains importance because of the use of ammonia as a cosolvent. 

The chemical properties of a protein are dictated by the chemical properties of the amino acids of which it is composed. There are many functional groups which may participate in reaction processes these include alkyl, hydroxy, carboxy, amino and thiol groups. Some of these groups can be used in protein immobilisation, for example, where the protein is covalently fixed to other materials using such functional groups. 

S. Rodriguez, K. T. Schroeder, M. M. Kayser, and J. D. Stewart, Asymmetric synthesis of I-hydroxy esters and a-alkyl-/ -hydroxy esters by recombinant Escherichia coli expressing enzymes from baker s yeast, J. Org. Chem. 2000, 65, 2586-2587. 

Toste s vanadium oxidation system currently has more limited scope, although it seems to be orthogonal to the Pd(II) system. Whereas the Pd-sparteine system was unable to effectively resolve a-hydroxycarbonyl compounds, these alcohols were resolved with high selectivity using vanadium(V) (Table 2) [11]. Benzylic and allylic a-hydroxycarbonyls performed well in the reactions (entries 1-3,6). Alkyl hydroxy esters were oxidized more slowly, but with high selectivity (entry 5). Activated alcohols not a to a carbonyl led to poor selectivity or low reactivity. 

Routledge, E.J., Parker, J., Odum, J., Ashby, J., and Sumpter, J.P., Some alkyl hydroxy benzoate preservatives (parabens) are estrogenic, Toxicol. Appl. Pharmacol., 153, 12-19, 1998. 

Alkyl-(chlor-alkyl)- -chlorid E2, 123 Alkyl-(hydroxy-alkyl)- E2, 123 Alkyl-phenyl- -ester... 

Acyl-l-phenylimino- El4b, 262 (En-amin -I- R — CO —Cl) Alkyl-hydroxy- IV/lc, 177... 

The general formula of the piperazine phenothiazine derivatives under study is presented in Fig. 11. In the structure of I, A = (un)branched C2—6 alkylene separating N atoms linked thereto by at least two carbon atoms R1 = H, halo, lower alkyl, lower alkoxy, etc. R2, R3, R4 and R5 = H, Me or Et R6 = H, lower alkyl, hydroxy lower alkyl, etc. 

Nevinol [Neville], TM for a series of (alkyl) hydroxy resins. 

R6 is H, Cj-Cg alkyl, (C1-C3 alkoxy) C2-Cg alkyl hydroxy C2-Cg alkyl, (R R8N)C2-Cg alkyl, (R7R8NCO)Ci-Cg alkyl, CONR7R8, CSNR7R8 or C(NH)NR7R8... 

The 3- and 5-hydroxy isothiazoles and the corresponding thiol compounds are either O- and S-or V-alkylated. Hydroxy compounds are readily converted to chloro derivatives. 3-Methoxy groups are reported not to be displaced by nucleophiles <84CHEC-I(6)l3l>, yet both alkoxy groups in a 3,4-diethoxy isothiazole can be displaced (see Section 3.05.7.5). 3-Methoxy-1,2-benzisothiazole and the 3- and 5-alkylthio groups in isothiazoles undergo displacement reactions. New reactions at the carbonyl group of saccharin derivatives have been reported (see Section 3.05.7.5). 

The complementary nature of the purely basic and the palladium-assisted alkylation in combination with the chemoselective epoxidation of either of the two double bonds of 2-phenylsul-fonyl-1,3-dienes102 makes these substrates useful synthons for multicoupling reactions. By changing the order of nucleophilic addition and epoxidation, three isomers of the alkylated hydroxy vinyl sulfone are available one of them, that depicted, by palladium-promoted reaction. Without sodium hydride, or in the absence of a nucleophile, / -hydride elimination to the corresponding dienol occurs. 

Benzoic acids bearing ortho alkyl, hydroxy, or amino substituents undergo loss of water through a rearrangement reaction similar to that observed for orf/zo-substituted benzoate esters, as illustrated at the end of Section 8.6J. 

The 3(S)-hydroxybutanoate 141 obtained by bakers yeast reduction of ethyl acetoacetate was the starting material providing the required chirality at C37 (Scheme 18). Stereoselective alkylation, hydroxy group protection, and aldehyde formation at C35 gave the anti-product 142. Aldol condensation with vinylbor-... 

The theory and practice of the VNS reactirais have been examined in detail by the group of Prof. M. Mgkosza (for reviews, see [14, 18, 20-22, 25, 36, 37]. This well-developed methodology has been extended to many organic reactions, such as direct introduction of alkyl, hydroxy, and amino substituents into electron-deficient arenes (mainly nitroarenes), azines, and nitro derivatives of heteroaromatic compounds. Several excellent reviews dedicated specially to the VNS reactions of heterocyclic compounds have been published [18, 132]. 

Carboxylic nitrile liquid and solid elastomers are used to prepare elastomer-modified epoxy liquid and solid resins when it is desirable to have the modifier in the epoxy portion of the system. This is effected through alkyl-hydroxy esterification reactions. This is covered in the literature for uncatalyzed liquid resins (9), for tert-amine catalyzed systems (10), for tert-phosphine catalyzed systems (11), for low molecular weight solid resins advanced from the liquid state (12) and for liquid and solid resins where an additional rubber vulcanization step is carried out in addition to the alkylhydroxy ester adducting step (13). Such adduct preparations offer formulation stability with a wide range of hardener types amines, anhydrides, catalytic, Lewis acids/bases. 

In connection with the elucidation of the structures of the products obtained upon reaction of the tropone (496) with perchloric acid, the 6-methoxy-substituted derivatives have been prepared by reaction of (496) with methyl iodide and silver fluoroborate. -Comparison of u.v. spectra indicated that the salts between the tropones (496) and perchloric acid were 6-hydroxy-derivatives of the perchlorate of (497). U.v. and n.m.r. spectra of the systems (496)—(499) are discussed and their properties and reactivities compared with the corresponding JV-phenyl-pyrrole analogue. A preliminary report of the polarographic, i.r., and u.v. spectroscopic properties, as well as the dipole moments, of both the C-annelated systems (496) and (497) without methyl groups in the thiophen ring and also the ion (500) with alkyl, hydroxy, and methoxy-groups in the seven-membered ring has been published. Values of piirR+ between 6 and 7 have been obtained for this system. The spectroscopic properties of metallocene derivatives such as (501)—(503) have also... 

The trans effect of alkyl, hydroxy-alkyl, and alkoxy-alkyl groups in [(H20)sCrR] ions (R = CH2OH, CH20Me, CH2CN, or CHMe2) have been established from studies of the 1 1 anation reactions with thiocyanate ion." The data are consistent with either a D or an Id mechanism ... 

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