Subject dioxirane oxidation

A series of meso-dihydrobenzoins was also subjected to oxidative desymmetrization. Three equivalents of the chiral ketone 88 again provided the chiral dioxirane as the active species [138, 139]. As shown in Table 10.14, enantiomeric excesses up to 60% were achieved. In addition to the meso diols themselves, acetonides also proved suitable substrates in two instances (Table 10.14). 

Dimesityldioxirane, a crystalline derivative, has been isolated by Sander and colleagues and subjected to X-ray analysis. The microwave and X-ray data both suggest that dioxiranes have an atypically long 0—0 bond in excess of 1.5 A. Those factors that determine the stability of dioxiranes are not yet completely understood but what is known today will be addressed in this review. A series of achiral, and more recently chiral oxygen atom transfer reagents, have been adapted to very selective applications in the preparation of complex epoxides and related products of oxidation. A detailed history and survey of the rather remarkable evolution of dioxirane chemistry and their numerous synthetic applications is presented in Chapter 14 of this volume by Adam and Cong-Gui Zhao. Our objective in this part of the review is to first provide a detailed theoretical description of the electronic nature of dioxiranes and then to describe the nuances of the mechanism of oxygen atom transfer to a variety of nucleophilic substrates. 

This sequel on contemporary dioxirane chemistry should leave little if any doubt in the interested reader s mind that these fascinating and entertaining three-membered-ring cyclic peroxides are very popular oxidants and stUl in much demand, as witnessed by the current intensive research activities. Since the last Patai volume on Organic Peroxides some twenty years ago , which could have hardly featured a chapter on this subject since it was then in its infancy, dioxirane chemistry has literally exploded and become established as a prominent field in peroxide chemistry, as manifested by the now well over a thousand publications on this subject. ... 

Historically, the unusual oxidizing power of the three-membered-ring cyclic peroxides was demonstrated for dimethyldioxirane (DMD) under in-situ conditions [3] subsequently, its isolation was achieved by distillation [4]. The ease of preparation and ready access of dilute (<0.10 m) acetone solutions of DMD constitute a major breakthrough, which revolutionized dioxirane chemistry, as witnessed by the numerous reviews on this subject [5-19]. 

Curci et al. subjected cyclodecyne 125 to epoxidation with methyl(trifluoromethyl)dioxirane and observed a mixture (7 1) of m-bicyclo[5.3.0]decan-2-one 126 and m-bicyclo[4.4.0]decan-2-one 127, these products presumably arising via respective 1,5- and 1,6-transannular insertion pathways into the intermediate oxirene (Scheme 62) <1992TL7929, 1996CHEC-II(1)145>. Prior to this report, Concannon and Ciabattoni had observed the product profiles arising from the oxidation of several cycloalkynes with MCPBA (Table 18) <1973JA3284>. 

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