Synthesis of 4″-alkoxy-1,1′:4′,1″-terphenyl-4-carboxylic acids

Key words: 
• 4″-alkoxy-1,1′′,1″-terphenyl-4-carboxylic acid /
• synthesis /
• 4′-bromo-4-hydroxy-1,1′-biphenyl /
• Suzuki coupling

Abstract: Objective To prepare 4″-alkoxy-1,1′:4′,1″-terphenyl-4-carboxylic acids(1),the key fatty acid chain which is pharmaceutical intermediates for the total synthesis of novel cyclohexalipopeptide antifungal agents such as Caspofungin analogs. Methods Starting from 4′-bromo-4-hydroxy-1,1′-biphenyl(2), Results target compounds 1_a-1_e were prepared via hydrocarbylation,halogen-mental exchange followed by condensation with triisopropyl borate and acid hydrolysis.