Past exam of the chemistry course of the year 4 of the natural sciences course of the University of Cambridge / 2022 / Paper 1 / 14 / d

Without a competing hydrocarbon and without a crown receptor, catalyst 1 can still oxidize accessible secondary C–H bonds in the chain. Expect a less site-selective mixture of secondary oxidation products, predominantly ketones when two peroxide equivalents are effectively used, rather than the recognition-selected remote product pattern of catalyst 2.

The strongly electron-withdrawing, protonated ammonium end makes nearby C–H bonds less reactive, so the distribution need not be statistically uniform over every methylene. More distant secondary positions are comparatively favorable, while primary terminal C–H oxidation is generally harder. alcohol intermediates, incomplete conversion and unproductive peroxide consumption are also possible. Exact regioisomer ratios or a guaranteed quantitative yield cannot be predicted from the supplied conditions.