Increasing Structural Diversity of Natural Products by Michael Addition with ortho-Quinone Methide as the Acceptor
Ge Liao1, Jie Fan1, Lena Ludwig-Radtke1
1Institut für Pharmazeutische Biologie und Biotechnologie , Philipps-Universität Marburg , Robert-Koch Straße 4 , Marburg 35037 , Germany.
Abstract:
The active form of clavatol, ortho-quinone methide, can be generated from hydroxyclavatol in an aqueous system and used as a highly reactive intermediate for coupling with diverse natural products under very mild conditions. These include flavonoids, hydroxynaphthalenes, coumarins, xanthones, anthraquinones, phloroglucinols, phenolic acids, indole derivatives, tyrosine analogues, and quinolines. The clavatol moiety was mainly attached via C-C bonds to the ortho- or para-positions of phenolic hydroxyl/amino groups and the C2-position of the indole ring.
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