The Reactions of Electron-Rich Heterocycles with Derivatives of Orthocarboxylic Acids; VIII. Proton Acid-Catalyzed Acylation of Indoles by 2-Alkoxy-1,3-dioxolanes

Article abstract of DOI:10.1002/ardp.19873200504

In acid-catalyzed reactions with 3-unsubstituted indoles 1, 2-alkoxy-1,3-dioxolanes 2a-c behave as acyl equivalents.Depending on the substitution patterns of the reaction partners, the 1,3-dioxolanium ions 3a-c, generated in situ from the cyclic ortho esters by the action of sulfosalicylic acid, react to form tris-(3-indolyl)alkanes 6 and 9, bis-(3-indolyl)ethenes 7, or 3-benzoylindoles 8.Analogous reactivity was observed with related acyclic ortho esters.