Hydroxylation at saturated carbon atoms

An oft encountered reaction in secondary metabolite biosynthesis is hydroxylation at saturated carbon atoms. These reactions are mediated by a mixed-function oxidase (or mono-oxygenase) i.e. an oxidase which uses molecular oxygen for hydroxylation, according to the 

These hydroxylations are stereospeciiic proceeding with retention of configuration [11, 16] (examples are cited in following Chapters). This is the expected result for an electrophilic substitution at saturated carbon, i.e. attack at the point of highest electron density which is the sigma bond itself [17]. 

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