Sulfinic acids, allylic fragmentation

The removal of an allylic functionality is always accompanied by an allylic rearrangement when it proceeds by a retro-ene reaction. In most cases such a reaction requires high temperatures as in the thermolysis of allylic or, preparatively more useful, propargylic ethers (Scheme 84), but allylic sulfinic acids undergo fragmentation slightly above room temperature with the potential of high stereocontrol, as the example demonstrates (equation 46). ... 

When the allylic sulfinamides are hydrolyzed under special conditions (classical methods like alkali-or acid-catalyzed hydrolysis did not work properly) the obtained allylic sulfinic acids are unstable and will fragment smoothly again with allylic rearrangement into terminal alkenes. 

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