(2E)-3-{2-oxo-1-azatricyclo[7.3.1.0^{5,13}]trideca-3,5,7,9(13)-tetraen-3-yl}prop-2-enoic acid
(2E)-3-{2-oxo-1-azatricyclo[7.3.1.05,13]trideca-3,5,7,9(13)-tetraen-3-yl}prop-2-enoic acid
3-{2-oxo-1-azatricyclo[7.3.1.0^{5,13}]trideca-3,5,7,9(13)-tetraen-3-yl}prop-2-enoic acid