Synthesis of (.+-.)-10, 22-dioxokopsane and (.+-.)-kopsanone, heptacyclic indole alkaloids. Synthetic and mechanistic studies

P Magnus, T Gallagher, P Brown…

Index: Magnus, Philip; Gallagher, Timothy; Brown, Peter; Huffman, John C. Journal of the American Chemical Society, 1984 , vol. 106, # 7 p. 2105 - 2114

Full Text: HTML

Citation Number: 83

Abstract

Results Indole-2, 3-quinodimethane Portion. Synthesis of the Homoannular Diene 7. N-[(4- Methoxyphenyl) sulfonyl]-2-methyl-indole-3-carboxaldehyde (1 l) l33I0 was condensed with 2-(pheny1thio) ethylamine and the resulting imine 12 treated with the mixed anhydride 13 (made from ethylchloroformate and 4-pentynoic acid) at 120 OC in chlorobenzene to give the 1, 4-dihydrocarbazole 14 (37%). Higher temperatures resulted in large