Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Polish Journal of Chemistry

1 2006

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: diastereoselective alkylation

Sortuj według:

Ogranicz wyniki do:

Application of Oppolzer's Sultam in the Synthesis of Cyclic alfa-Amino Acids and beta-Amino Acids

Woźniak D., Szymańska A., Ołdziej S., Łankiewicz L., Grzonka Z.

Polish Journal of Chemistry

2006

Vol. 80, nr 2

265-277

In this paper we describe the application of Oppolzer's sultam as a chiral auxiliary for the synthesis of cyclic alfa- and beta2-amino acids. The key step of the synthesis is stereoselective alkylation of sultam-derived glycine and beta-alanine Schiff's bases leading to diastereometrically pure products. Final compounds are obtained after mild acidic and next basic hydrolyses of auxiliary groups and can be directly converted into N-tert-butoxycarbonyl- or N-fluorenylmethoxycarbonyl derivatives useful in peptide synthesis. In the case of substrates alkylated with dihalogenoalkanes spontaneous cyclization occurring during removal of the auxiliary groups yields cyclic alfa-amino acids (proline homologues) with reasonable yield and stereoselectivity. Theoretical data explain the differences in tendency for cyclization between alfa- and beta-amino acids.