Asymmetric synthesis of cycloaliphatic α-amino acids with a norbornane skeleton
1990; Elsevier BV; Volume: 1; Issue: 6 Linguagem: Inglês
10.1016/0957-4166(90)90038-c
ISSN1362-511X
AutoresCarlos Cativiela, Pilar López, J. A. Mayoral,
Tópico(s)Cyclopropane Reaction Mechanisms
ResumoThe asymmetric synthesis of endo and exo 2-aminonorbornane-2-carboxylic acids is carried out via the Diels-Alder reaction between cyclopentadiene and (−)-menthyl N-acetyl-α,β-dehydroalaninate. It is shown that this dienophile is more reactive than the corresponding methyl ester, which opens the way for the use of chiral N-acetyl-α,β-dehydroalaninates as dienophiles in asymmetric Diels-Alder reactions. As high diastereofacial selectivity is obtained with what was previously considered a mediocre chiral auxiliary, the acetamido group must play an important role, which is discussed.
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