| Autor: |
Paul Buchschacher, Andor Furst, Werner Meier, Jean-Marie Cassal |
| Rok vydání: |
1977 |
| Předmět: |
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| Zdroj: |
Helvetica Chimica Acta. 60:2747-2755 |
| ISSN: |
0018-019X |
| DOI: |
10.1002/hlca.19770600826 |
| Popis: |
Contribution to the asymmetric synthesis of bicyclic compounds catalysed by optically active amino acids. Synthesis of (S)-2-pyrrolidinepropionic acid and (R)-4-amino-5-phenylvaleric acid The evaluation of literature data concerning the asymmetric cyclization of the prochiral monocyclic triketones 1 to the enediones 3 shows that catalysis with optically active α-amino acids of the (S)-series leads to an excess of products having the same absolute configuration as natural steroids at C (13), while those of the (R)-series favour the formation of the enantiomers (Scheme 1). With 1a as substrate an inverse asymmetric course was observed using the optically active β-amino acids 5, 8 and 10 as catalysts (Table 1). Furthermore, the synthesis of the optically active γ-amino acids 6 and 11 using the Arndt-Eistert process is described. The influence of these latter compounds on the asymmetric transformation of 1a into 3a has been investigated. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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