Brønsted acid-assisted intramolecular aminohydroxylation of N-alkenylsulfonamides under heavy metal-free conditions.

The intramolecular aminohydroxylation of N-alkenylsulfonamides proceeded under heavy metal-free conditions to give substituted prolinol derivatives in high yields. Oxone activated by catalytic Brønsted acid worked well as an electrophilic oxidant for this reaction.