نتایج جستجو برای: methyl ketones
تعداد نتایج: 117877 فیلتر نتایج به سال:
Catalytic synthesis of chiral spirocyclic ketones was accomplished via the Pd-catalyzed intramolecular α-arylation of α-substituted cyclic ketones. The obtained spirocyclic ketone could be converted into a bifunctional organocatalyst.
1. The fate of orally administered (14)C-labelled l-alpha-methyldopa has been examined in three normal men and in eight hypertensive patients who responded to the drug and three who did not. 2. The output of (14)C in the urine in 2 days and in the faeces in 4 days was not very different in any of the subjects. The normals excreted about 40% of the dose in the urine and 60% in the faeces, the re...
We present here a new, general, solid phase strategy for the synthesis of sequence independent peptidyl-fluoromethyl ketones using standard Fmoc peptide chemistry. Our method is based on the synthesis of bifunctional linkers which allows the incorporation of amino acid fluoromethyl ketone unit at the C-terminal end of peptide sequences. Application of this approach for the synthesis of activity...
A methanol extract of lyophilized Brickellia cavanillesii was quantitatively analyzed using gas chromatographic (GC) techniques. The chromatographic methods employed were (i) GC-flame ionization detector (GC-FID), (ii) GC-mass spectrometry (GC-MS), and (iii) purge and trap GC-MS (P&T GC-MS). Thirteen compounds were identified with a quality match of 90% and above using GC-MS. The compounds were...
Carroll rearrangement of b-keto esters derived from tertiary allylic alcohols, for example, 7, under basic conditions followed by decarboxylation of the resulting b-keto acids yielded the expected c,d-unsaturated methyl ketones 8 with a range of olefin geometries from 100:0 to 1:1.8 E=Z, depending on the relative steric requirements of the two groups at the allylic center. 2003 Elsevier Ltd. Al...
Female moths of Lyclene dharma dharma (Arctiidae, Lithosiinae) produced three pheromone components (I-III), which strongly stimulated male antennae. Using GC-MS analysis and chemical derivatizations, the following structures were estimated: 6-methyl-2-octadecanone (I), 14-methyl-2-octadecanone (II), and 6,14-dimethyl-2-octadecanone (III). While the stereochemistry of the chiral centers could no...
Cooking surface temperatures, steak thickness, and quality grade effects on volatile aroma compounds
Volatile aroma compounds were evaluated in USDA Top Choice and Select beef top loin steaks cut 1.3 cm (THIN) or 3.8 (THICK) cooked on a commercial flat grill at 177°C (LOW) 232°C (HIGH) surface temperature. Gas chromatography/mass spectrophotometry was used to evaluate volatile compounds. had more 2-octene less trimethyl pyrazine (P < 0.05) THIN than THICK steaks, whereas unaffected by s...
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