Double Duty for Cyanogen Bromide in a Cascade Synthesis of Cyanoepoxides

An unprecedented reaction mode of cyanogen bromide has been discovered. Under basic conditions, cyanogen bromide acts as an equivalent of both Br + and CN − to convert enolizable ketones into the corresponding cyanoepoxides in good yields. This unique reaction mode provides new, one‐pot access to densely substituted cyanoepoxides from easily available ketones (see scheme).