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Asymmetric Michael addition reactions using ethyl (S)-4,4-dimethylpyroglutamate as a chiral auxiliary

✍ Scribed by Jesús Ezquerra; Lourdes Prieto; Carmen Avendaño; José Luis Martos; Elena de la Cuesta

Book ID
104260598
Publisher
Elsevier Science
Year
1999
Tongue
French
Weight
216 KB
Volume
40
Category
Article
ISSN
0040-4039

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✦ Synopsis

Ethyl 4,4-dimethylpyroglutamate has been used as a chiral auxiliary for ~,[3-unsaturated acids in Michael addition reactions. The conjugate addition of Grignard reagents to the amides in the presence of copper iodide, tetramethylene diamine (TMEDA) and trimethylsilyl chloride, proceeded with high yields and excellent stereoselectivities, yielding after hydrolysis enantiomerically pure [3-substituted carboxylic acid derivatives.

📜 SIMILAR VOLUMES

ChemInform Abstract: Asymmetric Michael
ChemInform Abstract: Asymmetric Michael Addition Reactions Using Ethyl (S)-4,4-Dimethylpyroglutamate as a Chiral Auxiliary.
✍ Jesus Ezquerra; Lourdes Prieto; Carmen Avendano; Jose Luis Martos; Elena de la C 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 32 KB 👁 2 views

Asymmetric Michael Addition Reactions Using Ethyl (S)-4,4-Dimethylpyroglutamate as a Chiral Auxiliary. -High levels of diastereoselection are achieved by the use of (I) as chiral auxiliary for α,β-unsaturated acid chlorides (II) in Michael conjugated addition with Grignard-derived organocopper reag

(S)-Ethyl 4,4-dimethyl pyroglutamate as
(S)-Ethyl 4,4-dimethyl pyroglutamate as a new ‘quat’ chiral auxiliary in aldol condensations
✍ Jesús Ezquerra; Almudena Rubio; Justina Martín; JoséLuis García Navío 📂 Article 📅 1997 🏛 Elsevier Science 🌐 English ⚖ 152 KB

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