Snlfoninm salts

Let ns scrutinize this reaction on the example of phenyl dialkyl snlfoninm salts. According to Saveant (2002), rednctive cleavage of these salts obeys the stepwise mechanism. In other words,... 

The reaction in Scheme 5.11 gives the snlfoninm salt (anion CIO4 ) in a 90% yield (ronte a). One-electron reduction of the thianthrene cation-radical by anisole is the side reaction (ronte b). Route b leads to products with a 10% total yield. Addition of the dibenzodioxine cation-radical accelerates the reaction 200 times. The cation-radicals of thianthrene and dibenzodioxine are stable. Having been prepared separately, they are introdnced into the reaction as perchlorate salts. 

Upon addition of a base—triethylamine is often nsed—the snlfoninm salt 7 is deprotonated to give a snlfoninm ylide 8. The latter decomposes into the carbonyl componnd 2 and dimethyl sulfide 9 throngh /1-elimination via a cyclic transition state. 

---