Intramolecular cyclization of 1-chloro-5-methyl-5(aryl)-2,3-epoxyhexane

This study presents a novel synthetic strategy for the preparation of tetralin derivatives via Lewis acid-catalyzed intramolecular cyclization of 1-chloro-5-methyl-5-aryl-2,3-epoxyhexanes.Tetralin-based compounds are of significant interest due to their broad applications in medicinal chemistry, agrochemicals, and advanced materials.However, their synthesis through traditional pathways often involves harsh reaction conditions, poor selectivity, and low yields.In this work, an alternative approach employing Lewis acids as catalysts -specifically anhydrous aluminum chloride (AlCl3) -is developed and optimized for the selective transformation of alkylaromatic epoxides into tetralin-type structures.The reactions were performed under inert atmosphere using n-hexane or dichloroethane as solvents.The intramolecular cyclization reactions produced key target compounds, including 1,1-dimethyl-4-chloroethyl-1,2,3,4-tetrahydronaphthalen-3-ol (compound III) and 1,1,5,8-tetramethyl-4-chloromethyl-1,2,3,4tetrahydronaphthalen-3-ol (compound IV), in good yields.The formation of these derivatives was confirmed through IR and NMR spectroscopy as well as elemental analysis.Furthermore, the study systematically investigated the influence of temperature, solvent polarity, catalyst type, and molar ratios on reaction efficiency.The use of AlCl3 resulted in the highest yields and selectivity at low temperatures.This approach provides a clean, efficient, and reproducible route for constructing tetralin frameworks and highlights the potential of Lewis acid-mediated cyclization in modern synthetic organic chemistry