Give IUPAC names for the following alkyl halides: (FIGURE CANNOT COPY)

Name: Problem 1, Chapter 10: Organic Chemistry
Uploaded: 2020-06-27T19:30:45-08:00
Duration: 13 min 14 s
Channel: Tom Rutherford
Description: Give IUPAC names for the following alkyl halides: (FIGURE CANNOT COPY)

Give IUPAC names for the following alkyl halides: (FIGURE...

Key Concepts

IUPAC Nomenclature

IUPAC nomenclature is a systematic method for naming organic chemical compounds so that each name uniquely identifies a specific structure. It involves a series of rules that prioritize the selection of the longest carbon chain, the assignment of locants to substituents, and the use of standardized prefixes and suffixes to indicate functional groups. This system ensures clear and unambiguous communication within chemical sciences.

Alkyl Halides

Alkyl halides are organic compounds in which one or more hydrogen atoms in an alkane are replaced by halogen atoms such as fluorine, chlorine, bromine, or iodine. Their nomenclature follows the standard IUPAC rules, where the halogen is treated as a substituent on the parent hydrocarbon chain and is named using the prefix 'halo-'.

Parent Chain Selection

Identifying the parent chain is a fundamental step in IUPAC nomenclature. It involves selecting the longest continuous chain of carbon atoms in the molecule that contains the highest priority functional group or substituents. In the context of alkyl halides, this chain forms the base name of the compound, and it is numbered to provide the lowest possible numbers to the substituents.

Substituent Locant Assignment

Substituent locant assignment is the process of numbering the carbon atoms in the parent chain so that the substituents receive the lowest numeral positions possible. This minimizes ambiguity and ensures consistency in naming, as it directly affects the positions of halogen atoms or other groups attached to the chain.

Nomenclature of Halogen Substituents

In the nomenclature of alkyl halides, halogen atoms are indicated by the use of the appropriate halogen prefixes, such as 'fluoro-', 'chloro-', 'bromo-', or 'iodo-'. These prefixes are attached to the composite name of the substituted alkane, preceded by the locant numbers that indicate where on the carbon chain the halogen atoms are located.

Transcript

00:01 Okay, this problem is asking us to give the ipaq names for these alkyl halides.

00:05 I don't usually do this, but i already wrote down all the compounds just because i want to save time, and also because i think it's easier to understand aipac in terms of the skeletal structure of the molecules.

00:16 Let's zoom into the first one.

00:18 I recommend drawing out the skeletal structures and then following along.

00:22 So for this first one, here's the skeletal structure.

00:25 I'm going to start numbering according to the longest carbon chain.

00:28 So, one, two, three.

00:34 A question might arise, why did i start numbering in this direction as opposed to this direction? and that is because iodine is a substitute.

00:41 We want to put the substituents on the lowest numbered carbons.

00:46 So i didn't start this one at one, two, three, four, because iodine would be at carbon number four.

00:52 We would much rather have it be at carbon number one.

00:56 So, one, two, three, four, that is a four carbon chain that corresponds.

01:00 To butte.

01:02 We've heard of butane, butene, butene, butyne.

01:05 We need to know whether it is an alkan, alkyne, or alkyne.

01:08 We know it is an alkan because there are only single bonds.

01:12 So, butane.

01:16 Okay, next up, we identify the substituents.

01:19 So iodine at carbon number one.

01:23 So we put one iota.

01:28 The one is representative of the carbon number one, and ioto is representative of the iodine.

01:35 More substituents so we just put it all together one iota butane notice how i put a dash between the number and the letter that is because we always put dashes between numbers and letters we don't have to put dashes between seemingly different words like iota and butane and that's because we don't put dashes between any letters okay next step again we want to put the substituents on the lowest number carbon.

02:09 So let's try out this way first.

02:11 One, two.

02:12 We see a substituent at number two, noted.

02:15 But this way, if we go one, two, we see that we have a chlorine at carbon number one.

02:21 So we'd much rather go in this direction when naming.

02:26 Okay, so i'm going to number them.

02:27 One, two, three.

02:30 I can either give this one number four or this one number four.

02:32 It doesn't matter because i'm going to have a methyl substituent no matter what.

02:36 So one, two, three, four.

02:39 Okay, one, two, three, four, that is a four carbon compound, so it's going to be bute something.

02:45 I look quick, and i only say single bonds, so i know it's going to be a butane, because it is an alkan.

02:51 Next up, i look at all my substituents, so at carbon number one, i see chlorine, so one chloral.

02:59 At carbon number three, i see a methyl, a methyl group.

03:03 So three, methyl.

03:09 Okay, now we put it all together alphabetically.

03:11 So, 1, chloro -3 -methylane.

03:28 Okay, so by alphabetical, i mean, according to the substituents.

03:33 Because butane, even though that would come first, within all three of these, butane is the parent compound, so it goes last.

03:41 Okay, so 1 -chloro -3 -methylbutane, that would be the answer for that one.

03:46 Next up, we identify the longest carbon chain.

03:50 So let's try this way first.

03:51 So 1, 2, 3, 4, and then 5.

03:57 So there's a 5 carbon compound.

03:59 We see that we have a bromine at position number 1.

04:02 Okay, i'll note that, but let's try the other way.

04:05 So bromine at position number 1.

04:07 So let's try this way.

04:09 1, 2, 3, 4, 5.

04:12 We also have a bromine at position number 1, but on this direction, we have 2 method groups at number 2.

04:18 So even though this one, this direction, has a bromonet number one relative to that way.

04:24 We have a substituent at the next lowest number carbon at number two with this one.

04:30 So two methyl groups on carbon number two, whereas on carbon number two, if we were to go this way, we don't have anything.

04:37 So that is why we should go in the leftmost direction.

04:42 So this way.

04:44 So one, two, three, four, five.

04:48 Okay, five carbon compound.

04:50 To pent.

04:53 Only single bonds.

04:54 That means it is a pentane.

04:58 Okay, next up, identify the substituents.

05:02 So at carbon number one and carbon number five, i see bromines.

05:07 So, 1 comma, 5, die, bromo.

05:15 The 1 and the 5 correspond to the numbered carbons.

05:19 The die corresponds to the two bromines in this molecule, and then the bromo is representative of the bromines.

05:28 Okay, so 1 -5 -di -romo.

05:29 Notice why i put the comma between 1 and 5.

05:32 Between numbers, we put commas...

Please give Ace some feedback