1,5-bis(diphenylphosphanyl)pentane-1,5-dione

1,5,11,15-tetrathiacycloicosane-6,10,16,20-tetrone

3,9-dioxa-15-azabicyclo[9.3.1]pentadeca-1(15),11,13-triene-4,8-dione

3,9,17,23-Tetraoxa-29,30-diaza-tricyclo[23.3.1.111,15]triaconta-1(29),11,13,15(30),25,27-hexaene-4,8,18,22-tetraone