Propionic 2-hydroxy-2-methyl

R)- or (S)-3-hydroxy-2-methyl-propionic acid methyl ester... 

D-Phenyl propionates of methyl esters of racemic hydroxy acids were prepared by Hammarstrom and Hamberg [190] and used for the separation of enantiomers of these compounds on QF-1. The separation was successful with methyl 3-, 15-, 16- and-17-hydroxyoctadecanoates, whereas diastereoisomers of methyl 4-, 7- and 13-hydroxyocta-decanoic acids were not separated. The derivatives were prepared at room temperature reaction of the ester of the hydroxy acid with D-2-phenylpropionyl chloride in the presence of pyridine for 2 h. 

Plants. Hydroxylated at the methyl group with formation of 2-hydroxy methyl-4-chlorophenoxy propionic acid... 

Names synonyms OXYMETHOLONE l7 -hydroxy-2-hydroxymelhylenc-l7s-methyl-3-androstanonc 2-hydroxymeihylene l7-9-meihyl dihydroiestostcrone. PROMETHOLONE 2>-mcthyl-dihydro-tesiostcronc propionate 29r-methyl-S -androstane-17/)-ol-3-one-propionate. 

Both at 70 and 80 °C, selectivity starts to decrease above 60% conversion, but more rapidly at 80 °C (product yield at 95% conversion <60% at 80 C >75% yield at 70 °C). Selectivity loss at higher conversions can be explained by competing addition of coproduced water instead of methanol to the 3-methoxyacrylate intermediate. In contrast to the stable 3,3-dimethoxy methyl propionate acetal product formed by methanol addition, the hemiacetal 3-methoxy-3-hydroxy methyl propionate generated by addition of water is prone to overoxidation, especially at higher reaction temperatures. Consequently, 3,3-dimethoxy methyl propionate selectivity benefits from increasing the methanol/methyl acrylate ratio. The results of variation of methanol/methyl acrylate ratio on activity and selectivity are depicted in Chart 11.2c,d, respectively (Pd/Cu/Fe/methyl acrylate 1/500/500/25000 oxygen pressure 0.2 MPa). Whereas conversion rates are equal at different methanol/methyl acrylate ratios, 3,3-dimethoxy methyl propionate selectivity erodes to 50% above 90% conversion at a low methanol/methyl acrylate... 

Synonyms Lactic acid methyl ester Methyl-(S)-2-hydroxy propionate (-)-Methyl L-lactate Methyl S-(-)-lactate Propanoic acid, 2-hydroxy-, methyl ester, (S)-... 

As in the examples described earlier, the alkenylations are usually performed in acidic solvents such as acetic and propionic acids, which limits coexisting functional groups in substrates. In contrast, the authors developed a reaction system, Pd(OAc)2/Cu(OAc)2/LiOAc/dimethylformamide (DMF), which is applicable to the reaction of thiophenes and furans possessing acid-sensitive substituents [42]. For example, the diphenyl(hydroxy)methyl function in diphenyl(2-thienyl)methanol is tolerable under the weakly basic conditions, as shown in Scheme 18.41. The function can be subsequently substituted by Pd-catalyzed arylation with aryl bromides via C-C bond cleavage to produce the corresponding 2-alkenyl-5-arylthiophenes. 

C4H8O3 2-hydroxy-propionic acid methyl ester 547-64-8... 

Enantioselective Friedel-Crafts alkylation reactions were performed between substituted indoles and methyl trifluoropyruvate, using a chiral nonracemic C2-symmetric 2,2 -bipyridyl copper triflate complex as catalyst. The active copper(II) catalyst was generated in situ. The corresponding 3,3,3-trifluoro-2-hydroxy-2-indolyl-propionic acid methyl esters were formed in good yield (up to 79%), and in up to 90% enantiomeric excess (eq 18). 

Various methods for the synthesis of sC-stars were reported. C(CH20H)4 and EtC(CH20H)3 were used as initiators with various acids as promoters to polymerise eC in solution and bulk. The best control was obtained with we acid in 5-15 times excess (fumaric acid, pKa = 3.02, 90°C, 6—24h, n,arm = 1-3-5.7 kg/mol, Mw/Mn = 1.06—1.14 conversion of eC — 78-99%). Stronger acid gives broader distributions [155]. A 2,2-bis(hydroxy-methyl) propionic-acid-based hyperbranched polymer served as initiator for eC to generate a star polymer with up to 40 arms (Mn/arm < 5000 Mw/Mn = 1.4 2.6) [156]. A glycerol core with catalytic amounts of SnOct yielded a 3-arm PeC (Marm = l-7kg/mol, Mw/Mn = 1.45-1.68, 130°C, 48h) [157]. 

Chloro-9-fluoro-llb-hydroxy-16b-methyl-17-(l-oxopropoxy)-pregna-l,4-diene-3,20-dione. See Clobetasol propionate. 

Triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxy-phenyl)propionate] [36443-68-2]... 

A mixture of 50 grams of a-dl-1,2-diphenyl-2-hydroxy-3-methyl-4-dimethylaminobutane hydrochloride, 50 grams of propionic anhydride and 50 cc of pyridine was refluxed for about 5 hours. The reaction mixture was cooled to 50°C and ethyl ether was added to the point of incipient precipitation. The hydrochloride salt of 0 -dl-l,2-diphenyl-2-propion-oxy-3-methyl-4-dimethylamlnobutane formed in the reaction precipitated upon cooling and was removed by filtration and washed with anhydrous ether. On recrystallization from a mixture of methanol and ethyl acetate, a-dl-l, 2-diphenyl-2-propionoxy-3-methyl-4-dimethyl amlnobutane hydrochloride melted at 170°-171°C. 

C24H3,F20v5 80474-45-9) see Fluticasone propionate (6a, 11 p, 16ot, 17a)-6,9-difluoro-l 1-hydroxy- 16-methyl-3-oxo-17-(l-oxopropoxy)andro5ta-l 4-diene-17-carboxylic acid... 

Nofe. AMPA = amino-3-hydroxy-5--methyl-4-isoxazole propionate GABA=y-aminobutyric acid. 

Some derivatives of adamantane with antagonist or agonist effects have also been synthesized. For instance, monocationic and dicationic adamantane derivatives block the a-amino-3-hydroxy-5-methylisoxazole -propionic acid (AMPA) receptors, A-methyl-o-aspartate (NMDA) receptors [134—136] and 5-hydroxytryptamine (5-HT3) receptors [137]. 

AMPAR. (a-Amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptor a non-NMDA-type ionotropic transmembrane receptor for glutamate that mediates fast synaptic transmission in the central nervous system. 

Non-NMDA ionotropic glutamate receptors (the majority sodium channel containing) can be subdivided into a-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) (comprising cloned subunits GluRl ) and kainate (GluR5-7, KAl-2) preferring receptors, with native receptors most likely to comprise either homo- or heteromeric pentamers of these subunits. 

Abbreviations N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA), L(+)-2 amino-3-phosphonopropionic acid (L-AP3), 6-cyano-7-nitroqninoxaline (CNQ5Q, 2,3-dihydroxy-6-nitro-7-sulfamyl-benzo-f-quinoxaline (NBQX), 3-(2-carboxypiperazin-4-yl)-propyl-l-phosphonic acid (CPP), 7 Chlorokynnreic... 

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