Oxidations by methyl(trifluoromethyl)dioxirane. 3. Selective polyoxyfunctionalization of adamantane

Continued Progress towards Efficient Functionalization of Natural and Non‐natural Targets under Mild Conditions: Oxygenation by C−H Bond Activation with Dioxirane

“…[20] TFDO oxidation of alkanesa lso shows ah ighers electivity for tertiaryv ersus secondary CÀHb onds (R t s from 15 to over 250). [14,21] Remarkably,i ti sa ble to perform the selective bridgehead hydroxylationo fa damantane to tetrahydroxy adaman-tane in 74 %y ield (transformation 3). [21] Adamantane is highly reactive compared with other hydrocarbons, and many derivatives designed from adamantyl decoration have been developed for different applications, especially in medicinal chemistry.…”

“…[14,21] Remarkably,i ti sa ble to perform the selective bridgehead hydroxylationo fa damantane to tetrahydroxy adaman-tane in 74 %y ield (transformation 3). [21] Adamantane is highly reactive compared with other hydrocarbons, and many derivatives designed from adamantyl decoration have been developed for different applications, especially in medicinal chemistry. [22] In this reaction, kinetic studies show that TFDO is more reactive than DDO by af actor of approximately 10 3 .…”

“…[22] In this reaction, kinetic studies show that TFDO is more reactive than DDO by af actor of approximately 10 3 . [21] Also, the reaction with representative centropolyindanes (e.g.,f enestrindane, transformation 6) undergo selective oxygen atom insertion into their bridgehead CÀHb onds by employing dioxirane. [23] The stereospecific functionalization at the tertiary CÀH bond of 1,2-dimethylcyclohexane (transformation 2), [14a] as well as of cis-decalin (transformation 4) is preferred over primary and secondary CÀHb onds.…”

Three‐Membered Heterocycles. Structure and Reactivity

“…Asymmetric hydroxylations are also possible using chiral oxaziridines, such as the camphor derived reagents 816 and 817. As an illustrative example, the sodium enolate of phenylacetophenone (822) was treated with ( þ )-(10-camphorsulfonyl) oxaziradine (817) to provide the a-hydroxyketone 823 in 80% yield and 94% ee. This reagent was also useful in the diastereoselective preparation of 13 2 -hydroxylated chlorophylls (e.g., 825) [795].…”

“…For example, treatment of 2,3-dimethylbutane (840, Scheme 2.120) with 3-methyl-3-trifluoromethyldioxirane (841) (TFD) at low temperature results in rapid and almost quantitative conversion to tertiary alcohol 842 [816]. In general, tertiary sites are preferred to secondary, a phenomenon underscored by the oxidation of adamantane (843) with excess TFD, in which only tertiary sites are affected [817]. In a selectivity study, Curci and coworkers [818] found that these bridgehead sites were also preferred to cyclopropane methylene positions, as demonstrated by the smooth conversion of the spiro cyclopropyladamantane 846 into the monohydroxy derivative 847.…”