Efficient Generation of ortho-Quinone Methide: Application to the Biomimetic Syntheses of (±)-Schefflone and Tocopherol Trimers
摘要:
An efficient method using silver oxide-mediated oxidation for the synthesis of ortho-quinone methides has been developed and applied to the biomimetic syntheses of novel trimeric natural products, (+/-)-schefflone and tocopherol trimers. Further studies of the critical trimerization as well as substrate scope and limitations are also reported.
ortho-Quinone methides are useful transient synthetic intermediates in organic synthesis. These species are most often generated in situ by the acid- or base-mediated transformation of phenols that have been pre-functionalized at a benzylic position, or by biomimetic oxidation of the corresponding ortho-alkylphenols with metal oxidants or transition-metal complexes. Here we describe a method for the