On the racemisation of aspartic anhydride during its preparation

Buron, Frédéric; Deguest, Geoffrey; Bischoff, Laurent; Fruit, Corinne; Marsais, Francis

doi:10.1016/j.tetasy.2007.07.003

Cited by 10 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resultant triester is decarboxylated and saponified to the 3‐alkylglutaric acid using KOH; NaOH resulted in incomplete saponification 31. Dehydration of the diacid can efficiently be affected with trifluoroacetic anhydride in EtOAc at 37°C 32. PDG anhydride itself is reactive to amines and alcohols, thus it could react with PTX at three positions.…”

Section: Resultsmentioning

confidence: 99%

Validity and variability in visual assessment of stenosis severity in phantom bifurcation lesions: A survey in experts during the fifth meeting of the european bifurcation club

Girasis

Onuma

Schuurbiers

et al. 2011

Cathet Cardio Intervent

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Validity and variability in visual assessment of stenosis severity in phantom bifurcation lesions: A survey in experts during the fifth meeting of the european bifurcation club

Girasis

Onuma

Schuurbiers

et al. 2011

Cathet Cardio Intervent

View full text Add to dashboard Cite

show abstract

“…Acidic amino acids underwent amidation effectively (Scheme D), with glutamic acid cyclizing intramolecularly to give pyroglutamide 1 n and aspartic acid undergoing double amidation to give a diamide ( 1 o ). The increased degree of racemization for 1 o is probably due to a competing dehydrative mechanism involving a 5‐membered acid anhydride, known to have a propensity for racemization . The basic ( 1 q – s ) and amidic ( 1 t – u ) amino acids were somewhat less reactive (Scheme E, F), with only histidine giving an amide derived from benzylamine ( 1 r ).…”

Section: Resultsmentioning

confidence: 99%

“…The increased degree of racemization for 1o is probablyd ue to ac ompeting dehydrative mechanism involvinga5 -membered acid anhydride,k nown to have ap ropensity for racemization. [24] The basic (1q-s)a nd amidic (1t-u)a mino acids were somewhat less reactive (Sche-me 4E,F), with only histidine giving an amide derived from benzylamine (1r). As expected, lysine spontaneously cyclized to form a-aminocaprolactam 1s.…”

Section: Substrate Scope Of Borate-catalysed Amidationmentioning

confidence: 99%

Protecting‐Group‐Free Amidation of Amino Acids using Lewis Acid Catalysts

Sabatini

Karaluka

Lanigan

et al. 2018

Chemistry A European J

View full text Add to dashboard Cite

Amidation of unprotected amino acids has been investigated using a variety of ‘classical“ coupling reagents, stoichiometric or catalytic group(IV) metal salts, and boron Lewis acids. The scope of the reaction was explored through the attempted synthesis of amides derived from twenty natural, and several unnatural, amino acids, as well as a wide selection of primary and secondary amines. The study also examines the synthesis of medicinally relevant compounds, and the scalability of this direct amidation approach. Finally, we provide insight into the chemoselectivity observed in these reactions.

show abstract

“…31 Dehydration of the diacid can efficiently be affected with trifluoroacetic anhydride in EtOAc at 37°C. 32 PDG anhydride itself is reactive to amines and alcohols thus it could react with PTX at three positions. PTX is known to be reactive to glutaric anhydride at the 2′-OH position at room temperature.…”

Section: Resultsmentioning

confidence: 99%

A Dicarboxylic Fatty Acid Derivative of Paclitaxel for Albumin-Assisted Drug Delivery

Hackett

Shyamsunder

Hartranft

et al. 2012

Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

Paclitaxel is a potent chemotherapy for many cancers but it suffers from very poor solubility. Consequently the TAXOL formulation uses copious amounts of the surfactant Cremophor EL to solubilize the drug for injection resulting in severe hypersensitivity and neutropenia. In contrast to Cremophor EL, presented is a way to solubilize paclitaxel (PTX) by conjugation of a dicarboxylic fatty acid for specific binding to the ubiquitous protein, serum albumin. The conjugation chemistry was simplified to a single step using the activated anhydride form of 3-pentadecylglutaric (PDG) acid which is reactive to a variety of nucleophiles. The PDG derivative is less cytotoxic than the parent compound and was found to slowly hydrolyze to PTX (~5% over 72 h) in serum, tumor cytosol, and tumor tissue homogenate. When injected intravenously to tumor bearing mice, [3H]-PTX in the TAXOL formulation was cleared rapidly with a half-life of 7 hours. In the case of the PDG derivative of PTX, the drug is quickly distributed and approximately 20% of the injected dose remained in the vasculature experiencing a 23-h half-life. These improvements from modifying PTX with the PDG fatty acid present the opportunity for PDG to become a generic modification for the improvement of many therapeutics.

show abstract

On the racemisation of aspartic anhydride during its preparation

Cited by 10 publications

References 15 publications

Validity and variability in visual assessment of stenosis severity in phantom bifurcation lesions: A survey in experts during the fifth meeting of the european bifurcation club

Validity and variability in visual assessment of stenosis severity in phantom bifurcation lesions: A survey in experts during the fifth meeting of the european bifurcation club

Protecting‐Group‐Free Amidation of Amino Acids using Lewis Acid Catalysts

A Dicarboxylic Fatty Acid Derivative of Paclitaxel for Albumin-Assisted Drug Delivery

Contact Info

Product

Resources

About