Tetrahedron Letters

Synthesis of tribromobenzofuran and tribromobenzopyran derivatives from methyl 2-allyl-4, 5, 6-tribromo-3-hydroxybenzoate

FA Khan, L Soma

文献索引：Khan, Faiz Ahmed; Soma, Laxminarayana Tetrahedron Letters, 2007 , vol. 48, # 1 p. 85 - 88

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被引用次数: 8

摘要

Palladium (II)-catalyzed oxidative cyclization of methyl 2-allyl-4, 5, 6-tribromo-3- hydroxybenzoate 4 gave a mixture of methyl 5, 6, 7-tribromo-2-methyl-benzofuran-4- carboxylate 5 and methyl 6, 7, 8-tribromo-2H-1-benzopyran-5-carboxylate 6; the ratio of the two products varied between 71: 29 and 24: 76 depending on the reaction conditions. On the other hand, NBS or NIS mediated cyclization of 4 followed by treatment with NaOMe or ...