Peculiar Reaction Chemical Reactivity Behavior of 1,3-Oxathiolane-5-one Towards Various Reagents: Assisted by Molecular Modeling Studies and in Vitro Antioxidant and Cytotoxicity Evaluation

Chemical reactivity of 2-methyl-2-phenyl-1,3-oxathiolan-5-one (<b>1</b>) towards various reagents such as hydroxyaldehyde, ketone, α-β unsaturated carbonyl compounds, heterocyclic amine, hydrazine and hydrazide to give unpredicative opened and fused heterocyclic systems were investigated. Moreover, treatment of compound <b>1</b> with bromoester <b>8</b> to afford the respective fused system, 2-methyl-2-phenylfuro[3,2-d][1,3]oxathiol-5(6<i>H</i>)-one (<b>9</b>) was implemented. Besides, ¹H-¹H nuclear overhauser effect spectroscopy (NOESY) was used for full confirmation of compound <b>25</b>. In addition, the density functional theory (DFT) modeling studies outcomes were discussed and all of the new synthesized compounds were evaluated as antioxidant and cytotoxicity assay against Hepatocellular carcinoma (HePG-2) the cell line.