Asymmetric Synthesis of Bicyclic Amino Acids

The asymmetric synthesis of conformationally constrained a-amino acids and their incorporation into peptides are currently topics of great interest [47]. Much sought after are fused bicyclic a-amino acids having the N atom incorporated into a ring system [48]. Many of these amino acids display interesting pharmacological activities, and they have served as building blocks for the synthesis of pep- 

To conclude the asymmetric synthesis of the new bicyclic amino acids the protected amino acid 81 was treated with CF3SO3H in CH2CI2, affording the amino acid derivative 82 in high yield [51]. 

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Scheme 1.3.28 Asymmetric synthesis of bicyclic amino acids via Pauson-Khand cycloaddition of vinyl sulfoximines.

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