On September 30, 2013, Qiu, Haixiao; Padivitage, Nilusha L. T.; Frink, Lillian A.; Armstrong, Daniel W. published an article.COA of Formula: C5H10O3 The title of the article was Enantiomeric impurities in chiral catalysts, auxiliaries, and synthons used in enantioselective syntheses. Part 4. And the article contained the following:
The enantiomeric purity of chiral reagents used in asym. syntheses directly affects the apparent reaction selectivity and the product’s enantiomeric excess. Herein, 46 recently available chiral compounds were evaluated to determine their actual enantiomeric compositions They were not assayed previously and/or were introduced after 2006, when the last comprehensive evaluation of com. available chiral compounds is reported. These compounds are widely used in asym. syntheses as chiral synthons, catalysts, and auxiliaries. The enantioselective anal. methods include HPLC approaches using Chirobiotic, Cyclobond and LARIHC series chiral stationary phases, and GC approaches using Chiraldex chiral stationary phases. Accurate, efficient assays for selected compounds are given. All enantiomeric test results were categorized within five impurity levels (i.e., <0.01%, 0.01-0.1%, 0.1-1%, 1-10% and >10%). Different batches of the same reagent from the same company can have different levels of enantiomeric impurities. Many of the reagents tested have <0.1% enantiomeric impurities. Only one of the chiral compounds has an enantiomeric impurity exceeding 10%. The experimental process involved the reaction of (R)-Methyl 3-hydroxybutanoate(cas: 3976-69-0).COA of Formula: C5H10O3
The Article related to enantiomeric impurity determination chiral catalyst auxiliary synthon enantioselective synthesis, Organic Analytical Chemistry: Determinations and other aspects.COA of Formula: C5H10O3
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