“…The structures of β-BHC [16][17][18], γ-BHC [19,20], δ-BHC [21], and ε-BHC [22] were not only elucidated by electron diffraction and X-ray methods, but also by spectrophotometry and dipole moment techniques. Furthermore, these structures were chemically confirmed by the chlorination and/or alkaline dehydrochlorination of BHC isomers [23][24][25][26][27][28][29][30]. For example, Cristol reacted α-, γ-, and δ-BHC isomers with brucine and found that among these isomers, α-BHC is racemic [31].…”