Ethyl(methyl)dioxirane as an efficient reagent for the oxidation of nucleoside phosphites into phosphates under nonbasic anhydrous conditions.

A convenient method for the oxidation of nucleoside phosphites into phosphates under nonbasic and nonaqueous conditions using commercially available ethyl(methyl)dioxirane has been developed. This oxidation is effective with both N-protected and N-unprotected strategies.