Hock rearrangement

A brief screen of potential radical mediators revealed that most oxidants facilitated the tosyl group elimination (Table 4). However, two lead reagents were identified, azobisisobutyronitrile (AIBN) and cumene hydroperoxide (CHP), both of which delivered the product in >80% solution yield, while minimizing over-oxidation. Ultimately, CHP was selected due to its commercial availability and ease of handling—CHP is used in the commercial synthesis of acetone and phenol (via the Hock rearrangement)." ... 

Other references related to the Hock rearrangement are cited in the literature. " ... 

ADHl-catalysis. [463] The double bond at C-11/13 is reduced by DBR2, a member of the enoate reductase family, and the aldehyde dehydrogenase ALDHl leads to the oxidation product dihydroartemisinic acid. [464] The further oxidation cascade is non-enzymatic, however stereoselective, and yields (+)-artemis-inin via relatively unstable intermediates. Geoffrey D. Brown at the University of Reading was able to demonstrate, that the Hock rearrangement of a hydroperoxide, followed by oxidation of the resulting enol with triplet oxygen, are the key steps of this sequence. [465]... 

One proposed pathway for the formation of 4-HNE was described under Hock rearrangement. This mechanism has been invoked for the formation of 4-H(P)NE from 9-HPODE [61]. In the same study, it was found that (a-6 hydroperoxides form 4-H(P)NE through a different mechanism. A crucial finding was that 95-HPODE formed the aldehyde as a racemic mixture whereas 135-HPODE gave rise to chiral 45-H(P)NE. 

Rearrangement to Electron-Deficient Oxygen The Baeyer-Villiger oxidation, like the Hock rearrangement, is an example of a molecular rearrangement to oxygen. Examples are shown in Equations 6.9 and 6.10. The... 

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