Platinum-and acid-catalyzed enyne metathesis reactions: mechanistic studies and applications to the syntheses of streptorubin B and metacycloprodigiosin

A Fürstner, H Szillat, B Gabor…

Index: Fuerstner, Alois; Szillat, Hauke; Gabor, Barbara; Mynott, Richard Journal of the American Chemical Society, 1998 , vol. 120, # 33 p. 8305 - 8314

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Citation Number: 271

Abstract

Formal total syntheses of the antibiotics metacycloprodigiosin (2) and streptorubin B (3) are described, which are known to exhibit promising immunomodulating properties. The key step en route to their meta-bridged pyrrole core structures 5 and 7, respectively, consists of a metathesis reaction of electron-deficient enynes catalyzed by either platinum halides, hard Lewis acids, or HBF4. This transformation expands the pre-existing cycloalkene of the ...