Amino Acid Derivatives That Stabilize Secondary Structures of Polypeptides. 4. Practical Synthesis of 4-(Alkylamino)-3-cyano-6-azabicyclooct-3-enes (Ben Derivatives) as γ-Turn Templates

Article abstract of DOI:10.1021/jo00262a026

A practical synthesis of the conformationally restricted amino acid analogue methyl N-<4-<6-(benzyloxycarbonyl)-3-cyano-6-azabicyclo<3.2.1>oct-2-enyl>>-L-alaninate (12ab) from 4-hydroxyproline is described.Blocking and Barton cyanoethylation generates N-(