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(S)-Ethyl 4,4-dimethyl pyroglutamate as a new ‘quat’ chiral auxiliary in aldol condensations

✍ Scribed by Jesús Ezquerra; Almudena Rubio; Justina Martín; JoséLuis García Navío

Publisher
Elsevier Science
Year
1997
Tongue
English
Weight
152 KB
Volume
8
Category
Article
ISSN
0957-4166

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✦ Synopsis

Enolates I, derived from the N-propionyl derivative of the 'quat' chiral auxiliary (S)-ethyl 4,4-dimethyl pyroglutamate 4 undergo highly stereoselective aldol reactions, which upon hydrolysis and removal of the chiral auxiliary yields the (2R,3R)-3-hydroxy-2-methylpropionic acid 9 in homochiral form. Remarkably, the stereogenic center of 4 was not affected during all the chemical transformations and it could be regenerated after the process in 70% yield. (~

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ChemInform Abstract: (S)-Ethyl 4,4-Dimet
ChemInform Abstract: (S)-Ethyl 4,4-Dimethyl Pyroglutamate as a New “Quat” Chiral Auxiliary in Aldol Condensations.
✍ J. EZQUERRA; A. RUBIO; J. MARTIN; J. L. GARCIA NAVIO 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 29 KB 👁 1 views

The title pyroglutamate (II) is found to be an excellent auxiliary in stereoselective aldol reactions. Remarkably, the stereogenic center of (II) is not altered during all the transformations and (II) can be regenerated after the process in 70% yield. -(EZQUERRA, J.;

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✍ Rhalid Akkari; Monique Calmès; Delphine Di Malta; Françoise Escale; Jean Martine 📂 Article 📅 2003 🏛 Elsevier Science 🌐 English ⚖ 166 KB

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