187039-41-4Relevant academic research and scientific papers
Diastereoselective 1,3-dipolar cycloadditions and Michael reactions of azomethine ylides to (2R)-3-benzoyl-4-methylidene-2-phenyloxazolidin-5-one and (2S)-3-benzoyl-2-t-butyl-4-methylideneoxazolidin-5-one
Pyne, Stephen G.,Safaei-G., Javad,Schafer, Karl,Javidan, Abdollah,Skelton, Brian W.,White, Allan H.
, p. 137 - 158 (2007/10/03)
The 1,3-dipolar cycloaddition reactions of (1) and (11) with the azomethine ylides derived from N-benzylidene α-amino acid esters (2) proceed with good to high exo-diastereoselectivity giving the cycloadducts (4) and (12), respectively. The cycloaddition adducts can be converted to highly functionalised prolines (14), (15) and (17) in high enantiomeric purities. The Michael addition adducts of (1) and (11) with the azomethine ylides derived from the N-(disubstituted methylidene) α-amino acid esters (18), (19) and (33) allow for a practical synthesis of all four stereoisomers of 4-benzamidopyroglutamate. The stereochemistry of these cycloaddition and Michael adducts has been extensively determined by single-crystal X-ray structural analysis [compounds (4b), (5b,d), (12b,d), (13e), (15), (20), (21) and (27)]. Lithium-chelated transition state structures have been proposed to rationalize the stereochemical outcomes of these reactions.
Diastereoselective Michael Reactions of Azomethine Ylides to Chiral 4-Methyleneoxazolidin-5-ones: Synthesis of the Four Stereoisomers of 4-Benzamidopyroglutamate
Javidan, Abdollah,Schafer, Karl,Pyne, Stephen G.
, p. 100 - 102 (2007/10/03)
The diastereoselective Michael addition reactions of the azomethine ylides derived from the α-(alkylideneamino) esters 2, 3 and 17 with the chiral oxazolidinones 1 and 8 allow for a practical synthesis of all four stereoisomers of 4-benzamidopyroglutamate.
