Bromination and conversion of tetrahydro-1H-indene to bisoxirane with a new approach: synthesis, structural characterization by spectroscopic and theoretical methods, and biological analysis supported by DFT and docking.

Abstract

In this study, a new method for synthesizing diepoxides is proposed. Tetrahydroindene 1 was brominated with NBS in the presence of LiClO₄ and acetic acid, resulting in the formation of dibromodiacetate derivatives 2 and 3. Treatment of compounds 2 and 3 with NaOH in methanol produced a mixture of diepoxides 4 and 5. Additionally, direct bromination of tetrahydro-1H-indene yielded tetrabromo octahydroindene isomers 6 and 7. The structures of the compounds were characterized using spectroscopic techniques such as ¹H NMR, ¹³C NMR, APT, COSY, and XRD. The new method provides an easy and selective route to access epoxides for the synthesis of various chemicals. This study also highlights the selective formation of endo-exo and exo-exo orientations of the obtained diepoxides, distinguishing it from previous studies. The stability and properties of the stereoisomers were investigated using computational methods, revealing the most stable configurations. Reactive sites in the molecules were identified using contour diagrams and molecular electrostatic potential maps. The anticancer properties of the compounds were evaluated in silico, comparing them to 5-fluorouracil (5-FU) against several cancer cell lines. The compounds exhibited the most effective anticancer activity against MCF-7 cells, with the order of anticancer activities generally determined as 2 > 7 > 3 > 6 > 5 > 4 > 5-FU.