Photoreaction of Thiobenzamide with 2-Vinylfuran Analogues. Facile Synthesis of Tetracyclic Indole System

Photoreaction of thiobenzamide (1) with Zvinylfuran analogues(2) in benzene solution gives 1H-benzo[g]furo[2.3-elindolederivatives (35).The indole alkaloids are a very large family of natural products, and the syntheses of various indole systems have received considerable attention.2Although numerous synthetic routes to indole systems are well known, little is known about the facile synthetic mute to multicyclic indole system such as 1H-dibenz[e,g]indole and 1H-