298209-94-6Relevant articles and documents
Convenient Synthesis of 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic Acid and Its Derivatives as Doubly Constrained Nonproteinogenic Amino Acid Derivatives
Czombos, Jozsef,Aelterman, Wim,Tkachev, Alexey,Martins, Jose C.,Tourwe, Dirk,Peter, Antal,Toeth, Geza,Fueloep, Ferenc,De Kimpe, Norbert
, p. 5469 - 5475 (2000)
Three strategies for the synthesis of the novel, doubly constrained, 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid and its derivatives were evaluated. Only cyclocondensation of the mono(triphenyl)phosphonium salt derived from 1,2-bis(bromomethyl)benzene with N-alkoxycarbonyloxamates in 1,2-dimethoxyethane in the presence of potassium carbonate and subsequent cyclopropanation with dimethylsulfoxonium methylide in dimethyl sulfoxide furnished suitable O-and N-protected derivatives of 3,4-methano-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid in a convenient way. A detailed 2D DQF-COSY and 2D NOESY NMR analysis of the rotational isomerism of the latter bicyclic amino acid derivatives was performed. Various O- and N-protection protocols were worked out to afford access to a whole range of new derivatives of the title amino acid, suitable for peptide synthesis.
