Illustrated Glossary of Organic Chemistry

MTBE: Methyl tert-butyl ether. IUPAC name 2-methoxy-2-methylpropane. A simple aliphatic ether. Used until recently in California as a gasoline oxygenate to increase octane rating, until it was discovered that MTBE -- a suspect carcinogen at high concentrations -- was accumulating in municipal wells and other water sources. In the United States, ethanol has replaced MTBE as a fuel oxygenate.

Lewis structure
Ball and spoke
Space filling model
Molecular structure of MTBE.


Acid catalyst

Industrial scale synthesis of MTBE involves acid-catalyzed electrophilic addition of methanol to isobutylene (2-methylpropene). This addition reaction obeys Markovnikov's rule.