ISSN:
1434-193X
Keywords:
Amino acids
;
Diastereoselective alkylation
;
Oppolzer's sultam
;
Sultam-imine enolate
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
---As part of an ongoing project concerning the synthesis of nonnatural amino acids, we have now developed a general strategy for the preparation of β2-amino acids (or 2-aminocarboxylic acid derivatives). Our procedure involves the synthesis of the sultam β-alaninate precursor 5 whose alkylation led with high yields and excellent diastereoselectivity to the precursor of β2-homophenylalanine, β2-homoalanine, and β2-homoleucine. Subsequent deprotection and Boc-protection yielded the expected β2-amino acids. X-ray analysis of the alkylation product established that (-)-sultam yielded (R)-β2-amino acids, conversely (+)-sultam yielded the enantiomer. The topicity of this alkylation is in agreement with the alkylation of Oppolzer's precursor for the synthesis of α-amino acids and opposite to that observed for gem-dialkylation.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
