Alkanols

Alkanols are a class of saturated alcohols with the general formula CnH2n+2O. They consist of an alkyl group attached to a hydroxyl (-OH) group, giving a polar molecule capable of hydrogen bonding. The simplest members are methanol, ethanol, propanol, and butanol. IUPAC names typically end in -ol (for example, propan-1-ol); systematic names indicate the position of the hydroxyl group, and classifications as primary, secondary, or tertiary refer to the carbon bearing the -OH.

Physical properties of alkanols arise from the hydroxyl group. They are generally liquids at room temperature with boiling points higher than those of corresponding alkanes, due to hydrogen bonding; boiling points rise with increasing carbon chain length. Shorter alkanols are miscible with water, while longer ones become progressively less soluble in water. They are flammable and commonly used as solvents and intermediates in organic synthesis.

Production and uses vary by member. Ethanol is produced mainly by fermentation of sugars or by the hydration of ethene, and methanol is manufactured from synthesis gas. Higher alkanols are obtained through various petrochemical and renewable routes. Alkanols serve as solvents in laboratories and industry, as intermediates to produce esters, ethers, and other chemicals, and as feedstocks for fuels (notably bioethanol and, in some contexts, methanol in blends).

Reactions of alkanols center on the hydroxyl group. They can be oxidized (primary alcohols to aldehydes and then to carboxylic acids; secondary to ketones), dehydrated to give alkenes, or converted to alkyl halides and esters. They also participate in esterification with carboxylic acids and in various catalytic transformations.

Safety considerations reflect their flammability and potential toxicity; methanol is notably toxic, whereas ethanol is relatively less toxic but still hazardous in large doses.