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

摘要

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