Bioinspired Synthesis of Pinoxaden Metabolites Using a Site-Selective C-H Oxidation Strategy.

A bioinspired synthesis of Pinoxaden metabolites is described herein. A site-selective C-H oxidation strategy validated by density functional theory (DFT) calculations was devised for preparing metabolites . Oxidation of the benzylic C-H bond in tertiary alcohol using KSO and catalytic AgNO formed the desired metabolite that enabled access to metabolites and in a single step. Unlike most metal/persulfate-catalyzed transformations reported for the C-C and C-O bond formation reactions wherein the metal acts as a catalyst, we propose that Ag(I)/KSO plays the role of an initiator in the oxidation of intermediate to . Metabolite was subjected to a ruthenium tetroxide-mediated C-H oxidation to form metabolites and as a mixture that were purified to isolate pure standards of these metabolites. Metabolite was synthesized from readily available advanced intermediate a House-Meinwald-type rearrangement in one step using a base.