Aromatic Compounds Historically,benzene and its first derivatives had pleasant aromas,and were called aromatic compounds. Structure of Benzene Kekule Structure Kekule(1866)bravely proposed that benzene had a cyclic structure with three alternating C-C double and three C- C single bonds H H H Whilst this is reasonably close to accurate,it cannot be exactly correct since this would require that 1,2- dichlorobenzene existed as two isomeric forms,yet it was known that it did not. Ch16 Aromatic Compounds(landscape).docx page 1 Ch16 Aromatic Compounds (landscape).docx page 1 Aromatic Compounds Historically, benzene and its first derivatives had pleasant aromas, and were called aromatic compounds. Structure of Benzene Kekulé Structure Kekulé (1866) bravely proposed that benzene had a cyclic structure with three alternating C=C double and three C￾C single bonds. Whilst this is reasonably close to accurate, it cannot be exactly correct since this would require that 1,2- dichlorobenzene existed as two isomeric forms, yet it was known that it did not. C C C C C C H H H H H H