Kornblum DeLaMare rearrangements

The enantiomerically enriched 4-hydroxyenones 32 are an important class of chiral building blocks. This class of molecules has generally been obtained by the enzymatic or nonenzymatic catalytic desymmetrization of meso-cyclic diols 31 (or their derivatives) that can be prepared from the meso-endoperoxides 30 [32]. It is also well known that achiral bases such as NEt3 can promote the Kornblum-DeLaMare rearrangement of the meso-endoperoxides 30 [33]. This process is believed to proceed via the E2... 

This reaction was first reported by Kornblum and DeLaMare in 1951. It is primarily a base-promoted rearrangement of a peroxide into a ketone and an alcohol and is thus known as the Kornblum-DeLaMare reaction or Kornblum-DeLaMare rearrangement. ... 

The enantioselective Kornblum-DeLaMare rearrangement based on the desymmetriza-tion of meio-endoperoxides by a chiral base catalyst has recently been developed. ... 

Other references related to the Kornblum-DeLaMare rearrangement are cited in the literature. ... 

The Br0nsted-acid-catalysed rearrangement of t-butyl peroxides provides for the construction of 2,3-disubstituted furans via 1,2-aryl migration. t-Butyl peroxides are reported to be transformed into 2,3,5-trisubstituted or 2,5-disubstituted furans through a sequence of base-catalysed Kornblum-DeLaMare rearrangements and acid-promoted Paal-Knorr reactions (Scheme 70). °°... 

The most prevalent base-catalyzed reaction of an endoperoxide is the Kornblum-DeLaMare decomposition [97a] which leads to a hydroxy ketone by removal of a proton from the carbon adjacent to the peroxy linkage [9b,90b,97], The formation, in a basic solvent as acetone, of hydroxyfuranones 69 (Sch. 38) in the photo-oxygenation of a,a -unsubstituted furans might occur via a similar rearrangement [60e]. Attempts to induce asymmetry in endoperoxides with enantiotopic hydrogens or with chiral bases have led to moderate success [98]. The Et3N-catalyzed rearrangement of substituted cycloheptatriene endoperoxides 92 leads to... 

In addition to photolytic or thermolytic conditions, the endoperoxide rearrangement to ihs-epoxides can also be conducted in a catalytic version in the presence of metaloporphyrins (e.g., cobalt(ll) tet-raphenylporphyrin). An illustrative difference between base-catalyzed (Kornblum-DeLaMare reaction) and thermal rearrangement of a cyclopentadiene-derived endoperoxide 13 was described recently. When... 

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