4Omethylated

4Omethylated is a descriptive term used in chemistry and related fields to denote molecules that contain a methoxy group (–O–CH3) installed at the fourth position of a core framework, most commonly on an aromatic ring or a sugar ring. As a label, it is meant to indicate para- or 4-position substitution by a methoxy group relative to other substituents, rather than to identify a single, specific compound.

Structural scope and usage vary by context. In aromatic chemistry, 4Omethylated compounds refer to p-methoxylated derivatives where the methoxy group sits opposite a reference substituent on the ring. In carbohydrate chemistry, the term can describe 4-O-methylation of a sugar hydroxyl group. The descriptor is widely used in structure–activity studies, natural products literature, and synthetic libraries to categorize derivatives by the presence of a 4-position methoxy substituent.

Synthesis and occurrence. In nature, O-methylation is performed by methyltransferase enzymes using S-adenosyl-L-methionine (SAM) as the methyl donor. In synthetic chemistry, 4-O-methylation is achieved by O-alkylation of a hydroxy group with methylating agents such as methyl iodide, dimethyl sulfate, or methyl triflate, often under basic or phase-transfer conditions. Regioselectivity must be carefully controlled to place the methoxy group at the correct 4-position.

Properties and implications. Introducing a methoxy group at position 4 can influence lipophilicity, electron distribution, hydrogen-bonding capacity, and metabolic stability, potentially altering biological activity or material properties.

Notes. 4Omethylated is not a single compound but a structural feature used across multiple compounds. Precise naming should specify the core structure and substitution pattern to avoid ambiguity.