Naming organic compounds

2 marks · Easy

A compound has the structural formula below:

State the IUPAC name for this compound.

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

but-2-ene

Also accept: 2-butene

Common mistakes: butene; but-1-ene

Show mark scheme and worked solution

Marking points

M1 · 1 mark · Identifies the presence of a carbon-carbon double bond and the position (between carbons 2 and 3); recognises 4 carbons (but-).

A1 · 1 mark · States the correct name: but-2-ene (or 2-butene).

Worked solution

Count the number of carbons in the longest chain: 4 (so prefix is 'but-').

There is a double bond starting at carbon 2 (between the second and third carbon).

The correct IUPAC name is but-2-ene (or 2-butene).