Synthesis of a 4,6-Disubstituted Dibenzofuran β-Sheet Initiator by Reductive Radical Arylation of Benzene

Abstract

Tributyltin hydride mediated addition of 3-iodosalicylaldehyde to benzene in the presence of catalytic benzeneselenol affords (1,4-cyclohexadien-3-yl)salicylaldehyde. Homologation of the aldehyde group is followed by cycloetherification with dimethyl dioxirane to give a 4,6-disubstituted tetrahydrodibenzofuran. Adjustment of oxidation states and introduction of a second chain by Wittig olefination affords the β-sheet initiator, ethyl 4-(2-tert-butoxycarbonylaminoethyl)-6-dibenzofuranpropanoate.