A convergent synthesis of brevisamide (1) is described based on the application of the crotyl silane-based [4 + 2]-annulation used for the preparation of the advanced oxygenated tetrahydropyran intermediate 2. The side chain bearing a conjugated (E,E)-diene was efficiently constructed under modified Negishi cross-coupling conditions.
An improved synthesis of (−)-brevisamide, a marine monocyclic ether amide of dinoflagellate origin
作者:Ryosuke Tsutsumi、Takefumi Kuranaga、Jeffrey L.C. Wright、Daniel G. Baden、Emiko Ito、Masayuki Satake、Kazuo Tachibana
DOI:10.1016/j.tet.2010.06.074
日期:2010.8
An improved synthesis of (−)-brevisamide a marine cyclic ether isolated from the red-tide dinoflagellate Karenia brevis was achieved. The ether ring portion was constructed from an unsaturated lactone, which was prepared enantioselectively via an Evans aldol reaction and one-pot lactonization in the presence of excessive base after an Ando reaction. The ether ring and a dienol side chain fragment were
A convergent synthesis of brevisamide (1) is described based on the application of the crotyl silane-based [4 + 2]-annulation used for the preparation of the advanced oxygenated tetrahydropyran intermediate 2. The side chain bearing a conjugated (E,E)-diene was efficiently constructed under modified Negishi cross-coupling conditions.