Iron III Homoenolate

The overall sequence of cyclopropanation of a cyclic silyl enol ether, chlorination with FeCl3, and dehydrochlorination represents a very reliable one-carbon ring expansion method for cycloalkanomer (Table 11). 

Application of this ring enlargement and oxidation procedure to 2-alkoxy-l-siloxycyclopropanes incorporated in a large ring provides macrocyclic diketones which act as potent chelating agents for metal cations [50]. 

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