D. Donati et al., CONFORMATIONALLY CONSTRAINED TRYPTOPHAN ANALOGS - SYNTHESIS OF (+ )-(Z)-2-AMINO-2,3-METHANO-3-(INDOL-3-YL)-PROPANOIC AND )-(E)-2-AMINO-2,3-METHANO-3-(INDOL-3-YL)-PROPANOIC ACIDS/, Tetrahedron, 52(29), 1996, pp. 9901-9908
The syntheses of (+/-)-(Z)- and )-(E)-2-amino-2,3-methano-3-(indol-3-y
l)-propanoic acids (8 and 15) are reported. Key step in their preparat
ion is the cyclopropanation of an olefinic azlactone derivative, follo
wed by a suitable deprotection sequence. Copyright (C) 1996 Elsevier S
cience Ltd