How to Interpret and Draw the Structure of a Molecule from Its Name

By Arthur Winter

It’s just as important to be able to determine and draw the structure of an organic molecule from its name as it is to be able to determine the name of its structure. Although English reads from left to right, the best way to read a structure’s name is from right to left. For example, if you want to draw the structure for 4-t-butyl-2,3,5-trimethylheptane, you would start by first drawing the parent chain — heptane. Heptane is seven carbons long, so you draw a seven-carbon chain, as shown here.

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Then you number the carbon chain as shown here.

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Then you stick on the substituents. Substituents can be added in any order. A t-butyl group goes on the number-four carbon, as shown here.

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Then, methyl groups need to be plugged onto the carbons numbered two, three, and five, as shown here.

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That’s it! By reading the molecule from right to left, the structure is easily drawn from the name.