190. “Sulfur-containing polybromoindoles from the red alga Laurencia brongniartii”
     Tanaka, J.; Higa, T.; Bernardinelli, G.; Jefford, C.W.
     Tetrahedron 1989, 45, 7301-7310.

Six new polybromoindoles (9-14) have been isolated from the red alga Laurencia brongniartii. Two were optically active sulfoxides, the itomanindoles A (12) and B (13) and one was a bisindole (14). The structures of 12 and 14 were elucidated by X-ray analysis. The sulfoxides 12 and 13 were readily converted with diazomethane to the corresponding N-methyl derivatives. Treatment with acetic anhydride at room temperature gave the same indolenine (24) as the major product.

Indoles 9-14 were isolated from Laurencia brongniartii. Structures of 12 and 14 were elucidated by X-ray.

DOI : 10.1016/S0040-4020(01)89191-2 

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