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Methyl -pyroglutamate

The 2,2 -diindolylmethane 12 also undergoes reaction with pyr-rolidin-2-one and phosphoryl chloride to give the 7,7 -di-(l-pyrrolin-2-yl) derivative 55a in 36% yield.11,36 A significant by-product in this reaction is the calix[3]indole 56, which arises from the direct reaction of compound 12 with phosphoryl chloride22,23 (Scheme 17). A similar reaction with methyl pyroglutamate was less successful and gave only a... [Pg.99]

A new stereocontrolled synthetic route to the potent proteasome inhibitor omuralide 46 has been developed from methyl pyroglutamate <07JOC10108>. The development of a new convertible isocyanide, indole-isocyanide, for ready access to pyroglutamic acids has culminated in the formal total synthesis of omuralide featuring a stereocontrolled Ugi reaction <07OL3631>. A novel enantioselective total synthesis of 20S proteasome inhibitor salinosporamide A 47 included, as a key feature, an intramolecular aldol cyclization <07OL2289>. A concise total synthesis of ( )-salinosporamide A, ( )-cinnabaramide A, and derivatives via a bis-cyclization process has been documented <07OL2143>. The... [Pg.83]

Addition of phenylmagnesium chloride to methyl pyroglutamate followed by reduction with borane to give racemic a,a-diphenyl-2-pyrrolidinemelhanol (3 steps, 51% yield from pyrroglutamic acid) that was then resolved as its O-acetylmandelate salt 10 give (R)- or (S)-a,a-diphenyl-2-pyrrolidinemethanol (2 steps, 3 recrystallizations, 30% yield from racemic a,a-diphenyl-2-pyrrolidinemethanol ref. 5f). [Pg.69]

The second reported synthesis was by Martin and co-workers (Breimeman and Martin 2004 Brenneman, Machauer, and Martin 2004 Martin 2005). Fundamentally, this synthesis differs with respect to the previous one in the strategy for achieving the synthesis of the c/5-2,5-disubstituted pyrrolidine 71 (Scheme 7.17). The starting product in this case was the D-methyl pyroglutamate. [Pg.132]

Terpyrroles. POGI3 added with stirring at 0° under Ng during 0.5 hr. to a mixture of 5-methoxycarbonyl-2,2 -bipyrrole, methyl pyroglutamate, di-... [Pg.245]

The Rigo methodology [169] was also found to be unsuccessful for the alkylation of (5)-methyl 5-oxo-l-(trimethylsilyl)pyrrolidine-2-carboxylate (III-68) with 3-(2-bromoethyl)-l//-indole or 3-(2-((trimethylsilyl)oxy)ethyl)-17/-indole (Scheme 4.39) [166]. Under these conditions, only (L)-methyl pyroglutamate was formed. [Pg.140]

Figure 15.8 Multidimensional GC-MS separation of urinary acids after derivatization with methyl chloroformate (a) pre-column cliromatogram after splitless injection (h) Main-column selected ion monitoring cliromatogram (mass 84) of pyroglutamic acid methyl ester. Adapted from Journal of Chromatography, B 714, M. Heil et ai, Enantioselective multidimensional gas chromatography-mass spectrometry in the analysis of urinary organic acids , pp. 119-126, copyright 1998, with permission from Elsevier Science. Figure 15.8 Multidimensional GC-MS separation of urinary acids after derivatization with methyl chloroformate (a) pre-column cliromatogram after splitless injection (h) Main-column selected ion monitoring cliromatogram (mass 84) of pyroglutamic acid methyl ester. Adapted from Journal of Chromatography, B 714, M. Heil et ai, Enantioselective multidimensional gas chromatography-mass spectrometry in the analysis of urinary organic acids , pp. 119-126, copyright 1998, with permission from Elsevier Science.
A radical cyclization of a 2-chloroacyl enamine 157 was used to synthesize 2-substituted pyroglutamates 160. Usually, the radical 158 undergoes an initial 5-endo cyclization (path a) and the resulting intermediate 159 attacked electrophiles like methyl acrylate to give the pyroglutamate 160. Unexpectedly, the reaction with methyl methacrylate took another course and a seven-membered... [Pg.150]

The (R)-enantiomer of (242) has also been prepared and used as a chiral auxiliary in an enantioselective aldol synthesis of (+)-(S )-gingerol (79CB3703). (R )-Glutamic acid (246) was thus converted into (i )-pyroglutamic acid by simply heating in water. Conversion of (247) to its methyl ester and LAH reduction delivered alcohol (248). Ethyl nitrite treatment of (248) gave nitrosoamine (249), which was methylated to furnish (250). Exposure of (250) to LAH completed the synthesis of the required chiral auxiliary RAMP [(R)- l-amino-2-(methoxymethyl)pyrrolidine]. The hydrazone (252), derived from RAMP and acetone, was... [Pg.435]

Fig. 3. Hydrogenation of pyroglutamic acid (0.22 M) in water at 150°C and 13.7 Mpa of H2 with (A) 0.29 M phosphoric acid and (B) in absence of acid. 5HMP, pyroglutaminol (5-hydroxymethyl-2-pyrrolidinone). Note that small amounts of 2-pyrrolidinone and 5-methyl-2-pyrrolidinone were also formed. (Note mass balance refers to HPLC identifiable product, not actual mass balance.)... Fig. 3. Hydrogenation of pyroglutamic acid (0.22 M) in water at 150°C and 13.7 Mpa of H2 with (A) 0.29 M phosphoric acid and (B) in absence of acid. 5HMP, pyroglutaminol (5-hydroxymethyl-2-pyrrolidinone). Note that small amounts of 2-pyrrolidinone and 5-methyl-2-pyrrolidinone were also formed. (Note mass balance refers to HPLC identifiable product, not actual mass balance.)...
Glutamic acid 1,5-Pentanediol, 2-amino-1,5-pentanediol, 4-amino-5-hydroxypentanoic acid, 4- amino-butanoic acid, 5- methyl-2-pyrrolidinone, 5 -hydroxynorvol ine, 5-(hydroxymethyl)-2-pyrrol idinone, pyroglutamic acid, 5-caprolactone Food additives, polymers, solvent Hermann, 2003 Feuchtenberger etal., 2005 Corma etal., 2007... [Pg.84]

The same intermediate 74 was synthesized by J. W. Bruin et al74 by an alternative route. They reduced the ester function of the pyroglutamate with LiBH4 to the primary alcohol 75a which was protected as the acetate 75b to prevent O-alkylation. Reaction of the sodium salt of 75 b formed with NaH in dimethylformamide, with methyl-7-bromoheptanoate followed by methanolysis of the acetate function gave 74. Oxydation of the alcohol 74 by Pfitzner-Moffat-oxydation or oxydation with Collins reagent led to the unstable aldehyde 77. [Pg.65]

C5H7N03 L-pyroglutamic acid 98-79-3 25.00 1.2175 2 4932 C5H803 3-methyl-2-oxobutanoic acid 759-05-7 20.00 0.9968 1... [Pg.217]

Besson M, Debleqc F, Gallezot P, Neto S, Pinel C (2000) Diastereoselective heterogeneous catalytic hydrogenation of 2-methyl nicotinic acid using pyroglutamate chiral auxiliary. C Chem Eur J 6 949... [Pg.114]

Michael addition of metallated camphor derivatives of diethyl aminomethylphosphonate to diethyl vinylphosphonate followed by hydrolysis with 90% aqueous AcOH leads in 73% yield and high diastereoselectivity to tetraethyl A-acetyl 2-amino-l,3-propylenediphosphonate, a phosphonic analogue of glutaric acid (Scheme 8.8V). No racemization occurs under the hydrolysis conditions Similarly, methyl acrylate, after hydrolysis of diastereomerically pure adduct, leads to the phosphonic analogue of pyroglutamic acid further reduced with I.iBlI,/BF. t,() to the phosphoproline diethylester in 61% yield (Scheme 8.87). ... [Pg.468]


See other pages where Methyl -pyroglutamate is mentioned: [Pg.98]    [Pg.63]    [Pg.132]    [Pg.313]    [Pg.1032]    [Pg.98]    [Pg.63]    [Pg.132]    [Pg.313]    [Pg.1032]    [Pg.86]    [Pg.932]    [Pg.72]    [Pg.37]    [Pg.578]    [Pg.27]    [Pg.235]    [Pg.339]    [Pg.408]    [Pg.40]    [Pg.82]    [Pg.232]    [Pg.752]    [Pg.97]    [Pg.809]    [Pg.17]    [Pg.256]    [Pg.198]    [Pg.301]    [Pg.303]    [Pg.105]    [Pg.107]    [Pg.879]    [Pg.879]    [Pg.1042]    [Pg.303]   
See also in sourсe #XX -- [ Pg.303 ]

See also in sourсe #XX -- [ Pg.303 ]




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Pyroglutamates

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