This methodology gives acyclic and cyclic α-hydroxy ketones in high yield with a cheap, commercially available oxidant. An inherent problem with mCPBA is its inability to oxidize silyl ketene acetals. In order to synthesize α-hydroxy esters, different oxidants are needed such as NaOCl (see above), lead(IV) acetate, or a hypofluorous acid-acetonitrile (HOF-ACN) complex. The Rubottom group found that lead(IV) acetate in DCM or benzene gave good yields of acyclic and cyclic α-hydroxy esters after treatment of the crude reaction mixture with triethylammonium fluoride. Later, the highly electrophilic HOF-ACN complex was used by S. Rozen to oxidize a variety of electron rich silyl enol ethers, silyl ketene acetals, and bis(silyl acetals), derived from carboxylic acids, in good yields at or below room temperature. Applications in synthesis The following examples represent only a small portion of syntheses that highlight the use of the Rubottom oxidation to install an important α-hydroxy functionality. Some of the major features of the following syntheses include the use of buffered conditions to protect sensitive substrates and the diastereoselective installation of the α-hydroxy group due to substrate controlled facial bias. For more examples see refs The Rubottom oxidation was used in the synthesis of periplanone B, a sex pheromone excreted by the female American cockroach. The synthesis employed an anionic oxy-Cope rearrangement coupled to a Rubottom oxidation. After heating in the presence of potassium hydride (KH) and 18-crown-6 (18-C-6) to effect the anionic oxy-Cope, the enolate intermediate was trapped with trimethylsilyl chloride (TMSCl). The silyl enol ether intermediate could then be treated with mCPBA under Rubottom oxidation conditions to give the desired α-hydroxy carbonyl compound that could then be carried on to (±)-periplanone B and its diastereomers to prove its structure. Brevisamide, a proposed biosynthetic precursor for a polyether marine toxin, was synthesized by Ghosh and Li, one step of which is a Rubottom oxidation of the cyclic silyl enol ether under buffered conditions. Chiral chromium catalyst B was developed the Jacobsen group and confers high levels of enantio- and diastereoselectivity. The stereocenters conveniently set in the Diels-Alder reaction direct the oxidation to the less hindered face, giving a single diastereomer, which could then be carried on in 14 more steps to Brevisamide. Wang and coworkers developed a robust, kilogram-scale synthesis of the potent derivative 2S-hydroxymutilin from pleuromutilin, an antibiotic produced by various species of basidiomycetes. Basic hydrolysis to remove the hydroxyl ester moiety of pleuromutilin yielded mutilin.