Draw and name alkanes that meet the following descriptions:

Question

A 5-carbon alkane with a tertiary carbon atom

Accepted Answer

All right. Hi everyone. So this question says to draw the line structure of the alkane described a six carbon branched chain or cane with two tertiary carbon atoms provide the Iupac name. Now recall first and foremost, right, that a line structure or a skeletal structure is a representation of an organic molecule in which carbon carbon bonds are shown simply as lines. So essentially carbon atoms are not actually tr and every corner or open end is designated or represents a carbon atom. However, other atoms like nitrogen, oxygen and chlorine among others are always going to be shown. But how Eugene Adams for that matter ones that are connected to carbon to be specific are not actually shown instead, they are implied to fill however many bonds, carbon is missing according to the line structure. So with that being said, we can consider the description given here, we have six carbons in total, but the all cane itself is branched now because it's branched. Recall that there are going to be substituents that are attached to the parent chain but are not part of it. So with that in mind, we also know that there have to be two tertiary carbon atoms. Recall that a carbon atom is tertiary when it has three bonds to other carbon atoms. So because two carbon atoms have to be tertiary, there cannot simply be a straight chain of six carbons, rather a few of them have to be substituents. And because we need two tertiary carbons, there have to be two substituents that branch out of the parent chain. So if we have six carbons in total, the minimum substituent in this case would be a methyl group or a CH three. So if I subtract two from the six total carbons, that means that the parent chain has to be or carbons long. So to represent this, I will draw a zigzag with four corners and open ends. So now the question is to find where our substituents will be. As we discussed. Previously, we're going to require two methyl substituents on the molecule. But if we were to add them to positions one or four, we would simply be extending the parent chain. So instead, right, we can place one methyl group on carbon two and another on carbon three. So now all criteria are met, right? We have six carbons in total. The Alcaine is branched and two of our carbon atoms are tertiary. So now lets talk about the parrot date or the Iupac name. Excuse me. The first step I always like to do is to find the parent name of the molecule because the parent chain is four carbons long, that parent name is going to be beating. And in this case, we only have one type of substituent in this case, a methyl group. But recall that when it comes to Iupac naming, when you have multiple of the same substituent, a prefix has to be added to indicate their quantity, right. So because I have two methyl groups in the same molecule, the prefix would have to be dye, meaning that my name here is going to be dimethyl. So for every substituent also there has to be a number indicating the position on the parent chain. So because one methyl group is on position two, whereas the other is on position three, I will put this together as two comma three dash dimethyl. Notice how commas are used to separate numbers from each other. Whereas dashes are used to separate numbers from letters. So now the substituents names and positions are combined with the name of the parent chain with no space in between them, right? So that becomes 23 dimethyl butane with no spaces in between and there you have it here is the correct line structure and the correct Iupac named is 23 dimethyl butane. So with that being said, thank you so very much for watching and I hope you found this helpful

Draw and name alkanes that meet the following descriptions:

A 5-carbon alkane with a tertiary carbon atom

Key Concepts

Alkanes

Tertiary Carbon

Structural Isomers

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