Abstract
As a result of the enhanced reactivity of the endo-cyclic tin---carbon bond 1,1-dimethyl-1-stannacyclopentane readily undergoes ring-expansion reactions with a variety of substrates to produce new organotin heterocycles. Illustrative examples include ring-expansion reactions with oxygen, sulphur, sulphur dioxide, diiron noncarbonyl, dichlorocarbene and diethyl azodicarboxylate.