Mechanism-based inactivation of serine proteases by dichlorocyclopropane fused lactone derivatives

A dichlorocyclopropane fused lactone derivative was prepared as a novel mechanism-based inactivator of serine protease, α-chymotrypsin. The lactone derivative showed transient irreversible inhibitory activity toward α-chymotrypsin with the value of Kobsd/[I] = 54 M−1s−1 and the enzyme activity recovered perfectly after 6 hours.