Illustrated Glossary of Organic Chemistry

Diamorphine (heroin): An alkaloid natural product with analgesic properties, and having the molecular structure shown below.  Diamorphine has a faster onset ('rush') than morphine or codeine, but a lesser duration. (This is a significant contributor to its addictive nature.) Diamorphine is synthesized from morphine by esterification of morphine's two hydroxyl groups. The name 'heroin' is generally used only when discussing the drug used illegally.

Diamorphine (heroin)