Introduction <P>Dimethyldioxirane (DMD), a nonmetal organic oxidant, has the ability to transfer
an oxygen atom to a wide range of substrates and functionalities, including C=C and
C-H bonds in hydrocarbons as well as atoms containing lone pairs such as sulfide,
[
1 ]
primary and secondary amines.
[
2 ]
This nonmetal electrophilic oxygen transfer agent is the reagent of choice for most
epoxidation reactions (better than MCPBA) due to its substrate-induced selectivity,
specificity, and reactivity under mild conditions (at 0-25 °C and neutral pH). It
reacts rapidly and in high yield, is easy to handle and applicable to acid- or base-sensitive
substrates, and it can be used to synthesize hydrolytically labile oxyfunctionalized
products.
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3-4 ]
</P><P>DMD-mediated halogenations,
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5a ]
hydroxylations,
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5b ]
and oxidations are widely used in the chemistry of flavonoids, low-molecular-weight
natural compounds and in expanding the organoborane chemistry.
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6a ]
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b ]
It also acts as a G-specific chemical sequencing agent and is a new source of singlet
oxygen generation.
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7a,b ]
</P>
Preparation <P>DMD is easily prepared by oxidizing acetone with commercially available low-cost
potassium peroxymonosulfate KHSO
5 (Oxone, Caroate) in water buffered at pH 7-7.5 using NaHCO
3 (Scheme
[
1 ]
). It is obtained as yellow solution in acetone in the range of 0.07-0.09 M concentration
and usually stored in the freezer (-25 °C).
[
3 ]
</P>
Scheme 1
