TETRAHEDRON, cilt.73, sa.8, ss.1135-1142, 2017 (SCI-Expanded)
This article reports the synthesis of some new spiro-beta-lactams bearing an indeno[1,2-b]quinoxaline ring system, prepared by a [2 + 2] cycloaddition of ketenes with imines derived from 11-H-indeno[1,2-b] quinoxalin-11-one. The structures of newly synthesized spiro-beta-lactams 2a-i and 3a-i were characterized by FT-IR, H-1 NMR, C-13 NMR, mass spectrometry and elemental analyses. The relative stereochemistry of spiro-beta-lactams 2a and 3a was determined unequivocally by X-ray crystallographic studies. (C) 2017 Elsevier Ltd. All rights reserved.