Trimethylenemethane (TMM) is a known intermediate which can be represented as 4 carbon conjugated structure of diradical or zwitterion. TMM has been shown to react with carbonyl-, iminyl-, cyano- groups and C-C double or triple bonds. Also its reaction with CO2 has been reported previously. Herein, we unveil novel TMM reactivity towards SO2. TMM is generated in situ from easily attainable methylenecyclopropanes 1 through palladium catalysis, then TMM reacts with dissolved SO2 yielding γ-sultines 2. Investigation of γ-sultine 2 reactivity has shown that these products are benchstable, but can regenerate TMM through palladium catalysis, reacting with a nucleophile under milder conditions than described in literature.