metoksiryhmästä

The methoxy group, often abbreviated as MeO-, is a functional group in organic chemistry. It consists of an oxygen atom connected to a methyl group. The methyl group is a hydrocarbon substituent derived from methane, with the chemical formula -CH3. Therefore, the methoxy group has the chemical formula -OCH3.

This group is commonly found in organic compounds, particularly in ethers and esters. When attached to an aromatic ring, such as in anisole, it significantly influences the reactivity and physical properties of the molecule. The methoxy group is electron-donating through resonance, which activates the aromatic ring towards electrophilic substitution reactions, typically directing substituents to the ortho and para positions.

In biological systems, the methoxy group is present in various natural products and pharmaceuticals. For example, it is a component of many alkaloids, flavonoids, and certain amino acids like methionine. Its presence can affect a molecule's solubility, lipophilicity, and its ability to interact with biological targets. The methoxy group is generally considered relatively stable and can be cleaved under specific harsh conditions, such as treatment with strong acids like hydroiodic acid. Its introduction into a molecule can be achieved through various synthetic methods, including Williamson ether synthesis or by methylation of a hydroxyl group.