29.1.3—Systematic nomenclature of simple aliphatic

Systematic naming selects the parent chain or ring, numbers it to give the principal functional group the lowest possible locant, then adds substituents and unsaturation prefixes.

For the syllabus range, use straight-chain esters and nitriles within the stated carbon limits, and cyclic compounds with one ring of up to six carbons. The suffix identifies the principal functional group.

CH₃CH₂CH₂OH is propan-1-ol, not propan-3-ol: numbering starts at the end nearest –OH. CH₃COOCH₂CH₃ is ethyl ethanoate, named as the alkyl group from the alcohol plus the carboxylate part.

The longest chain is not always numbered from the left, and the first number in an ester name does not describe the acid fragment.