Illustrated Glossary of Organic Chemistry

Grob fragmentation: A molecular fragmentation with the following pattern: A-B-C-D-E fragments to become A=B + C=D + E.

Deprotonation of 3-iodo-1-propanol with hydride ion affords an alkoxide. This alkoxide suffers Grob fragmentation to produce formaldehyde, ethylene, and iodide ion.