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Alkane Naming & Drawing · Acedra
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Alkane Naming & Drawing
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additional naming and drawing practice one to dichloro propane I'm gonna start by drawing propane the skeletal structure of propane looks like this it's three carbons remember there's a carbon at every end and Bend then I'm going to put a chlorine atom at carbons 1 & 2 so that will put a chlorine here and a chlorine here so that is one two dichloro propane now it's just as correct to
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knit to label this carbon one and this carbon two they are identical molecules pentane pentane is a carbon chain that has carbons and hydrogen's and there are five carbons pent is four five so we have one two three four five carbons here two four five tri methyl octane I'm going to start with the octane and I'm going to make eight carbons so here's one two three four five six seven eight so
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there's my eight carbons and I'm gonna leave them numbered like this 2 4 5 try methyl tells me that I have three methyl groups one is it carbon 2 one is it carbon 4 and one is it carbon five so that is 2 4 5 tri methyl Achtung you don't necessarily need to leave these numbers here it's there for illustrative purposes so that everybody can get used to how these how the carbons are numbered
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1 bromo butane so I have four carbons in a chain and then on my first carbon I'm going to put my bromine atom it is just as correct to put your bromine on this side that can be carbon one as well the next one for ethyl nonane so I'm going to start with na name that's nine carbon atoms there six seven eight nine just double check one two three four five six seven eight nine and on the
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fourth carbon I'm going to put an ethyl group so to show an ethyl group I would do this this is one carbon this is two carbons so that is the skeletal structure for four ethyl nonane now I'm going to draw two bromo 3-ethyl pentane so I need my five carbon backbone for pentane then I need a bromine on carbon 2 and on carbon 3 I need an ethyl group so it would look like that - 4 dimethyl hexane so
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here's my hexane carbon 2 gets a methyl carbon 4 gets a methyl 2 methyl butane there's my four carbons for butane here's my methyl so that is 2 methyl butane cyclohexane to draw cyclohexane we would draw a hexagon remember there is a carbon at every end and bend in each of these angle points is a carbon so there's my six carbons for the hexane cyclo means it's joined in a ring 3 methyl for ethyl heptane 1 2 3 4 5 6 for heptane so on carbon 3 I'm gonna put a methyl group and
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on carbon 4 I put an ethyl group now I'm going to name from drawings when you go to name from drawings you start by finding the longest carbon chain that you can you can hold your pen or pencil down on without breaking so here is my longest carbon chain that's going to be my parent chain or my backbone and I'm going to count so I have 1 2 3 4 5 I have 6 carbons there that means I'm going to start with hexane now I need to name a number of my substituents I have a 2 methyl I'm
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gonna write them over here on purpose and I have a 3 bromo now I know that it's 2 & 3 because if I go the other way if I if I number it the other way just with my green numbers here 1 2 3 4 5 6 then my substituents would be 4 bromo 5-methyl because 2 & 3 are less than 4 & 5 we're going to go with the original way so 2 metval 3 bromo but how do we order that in order to name it well this is where
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we use our alphabetical order so this would be 3 bromo 2 methyl hexane now for the next one again I'm going to find my longest carbon chain that contains my functional groups or substituents and in this case it looks like I have eight but let's count that 1 2 3 6 7 that is 8 that means I have an octane here now I need to name a number my substituents I have two methyl substituents in there on carbons 2 & 4 so this would be 2 4 dye methyl octane the next one again finding that
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longest carbon chain which could be called the parent chain or the backbone and this time it looks like I have five carbons one two three four five carbons now I numbered it this way instead of from the left and that's because both of my substituents are over here on the right so I have a pentane and this methyl group here this is a substituent so it is you would not name this as a hexane this is a pentane now I have a methyl group at carbon 2 and I have a chloro at carbon 1
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again with our alphabetical order this would be one chloro two methyl pentane the next one with our alphabetical order not our alphabetical order first we're going to find our longest carbon chain now which way do we go do we go up here or do we go down here and the answer is it doesn't matter because they are the same length so one of those is going to be a substituent and the other one is
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going to be part of the backbone and it doesn't matter which one so i number to find out how many carbons i have i have seven that means my parent chain or my backbone is a heptane now I have three substituents I have a methyl group at carbon two I have a fluoro at carbon three and at carbon five I have an ethyl so now I need to put these in alphabetical order we're gonna go EFM so it'll
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be five ethyl three fluoro two methyl heptane for the next one again with the parent chain count the carbons I have one two three four five six seven carbons so I have another heptane and I have three substituents I have a methyl a chlorine and a bromine so the way I have this number this would be three methyl five chloro and six bromo but what happens if I number it the opposite direction if
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this is carbon one two three four five then I would have to bromo three chloro and 5-methyl now because the green numbers these numbers down here at the bottom are less than than the original numbers my blue numbers although we still have a Jane I'm going to number the substituents this way from the right so we put this in alphabetical order we end up with two bromo three chloro five methyl heptane now we have a functional group this time we have a double bond we still find
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that longest carbon chain hopefully that contains the substituent V or the functional group in this case the double bond and we count the number of carbons we have in that chain so here we have five carbons this is going to be a pent but it's not a pentane it's a pent een that ecig no Phi's that we have a double bond now if I number from the left that double bond starts right here at
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carbon three so that would be a three pentene if i number from the right however the core the double bond starts here at carbon two we want to reduce that number so this would be two pentane the next one again with the longest carbon chain finding that backbone so we have one two three four five six we have seven carbons again with the heptane we have three substituents this time they're all
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the same so we would have two three four and this would be tri methyl heptane now this should be an easy one this is just three carbons there are no functional groups there are no substituent so we would call this propane here we have four carbons again no substituents no functional groups this is just butane and here count your carbons just six carbons no functional groups no substituents this is just hexane now you may want to get into practice of calling this like n hexane
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and butane but that's not something that I'm going to need from you quite yet so now let's work with some functional groups the rules are the same you find the longest carbon chain the backbone or the parent chain that contains the functional group so here we have this functional group this is an alcohol group this alcohol group will will give the ending oh L so we name the longest carbon chain as if it is a hydrocarbon then what we're going to do is take the e off and add Oh L so
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this is butanol but we can't just call it butanol we have to say where that Oh H group is so this is 2 butanol this next one I'm gonna go down and then over so this next one we have one two three four carbons (This is an error! "Butanal" is incorrect. That is pentanal. EVERY carbon, including the carbonyl, is counted.) so we would name it as if it is an alkane and then notice that functional group this is an aldehyde so the aldehyde gives the ending al butan now now
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you don't need to say it's 1 butan now because aldehydes are terminal groups they're always going to be at number one unless there's another functional group we'll get to more functional groups here in a minute this next one looks like propane down here the backbone is three carbons long so we would name that propane but we have a functional group and that functional group is a ketone ketones add the ending o n e and we pronounce that own not one so we take off the e
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and then add the o-n-e and that's propanone now the only way that propanone can exist is if the ketone is on number two however to be thorough we would put two propanone just to get you used to numbering where your functional groups are now similarly we have this molecule again with the three carbon chain we would name that propane notice the functional group the functional group is an alcohol alcohol means we take the e off and we add Oh L but we can't just call this
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propanol because we have to indicate where it is it's either gonna be on carbon 1 or carbon 2 and in this case it's on carbon 2 2-propanol would be the I you pack name now the common name would be to call this isopropanol the common name of this is acetone so these are the solvents that you were asked to buy to finish your kit now here we have what is called an ether we have common and I you
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pack names for ethers now the I you pack name just like the other rules you find your longest carbon chain here we have 2 carbons and gonna change my color and then here we only have the one carbon see the oxygen in the middle so because we have two carbons in our longest carbon chain we would name this ethane then on I would call this carbon 1 and carbon 2 we would name this bit as a substituent so this would be called methoxy so we would call this methoxy ethane that's the I you
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pack name the common name would be to name each arm of the ether and then add the word ether so each arm means the left side here that's an ethyl and then the right side is a methyl and then we would write the word ether ethyl methyl ether and these bits get alphabetized it's not left and right necessarily it's alphabetical order so that's the common name for an ether here we have I let's see one two three carbons in here we have two carbons so the I you pack name would then be
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to name the longest carbon chain which would be propane and then on carbon 2 we would name this as a substituent so this would be 2 F oxy oxy yes - with oxy propane to name it commonly we would call this isopropyl and then this group is an ethyl put those in alphabetical order we have ethyl isopropyl ether and there should be spaces between each of those I'm just getting running out of room so now we have a die ether here and that looks tricky but to name it with the IU PAC
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system we still find that longest carbon chain and here it is three carbons long and then we have our substituents these two substituents they are the same so we would call this one three die methoxy propane and that's all there is to it it looks like a complicated molecule but you still use the same rules find that longest carbon chain locate the substituents name this is substitute substituents give them numbers and write it out so here we have a cyclo hexane and this
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cyclohexane has a methyl substituent now because there is only one substituent we don't really need to have a number there if we had more than one substituent we definitely need to have numbers so this is cyclo hexane that is the parent chain and then we have a chloro and a bromo now I could call this one chloro three bromo because i would number this to decrease my numbers as much as possible or
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I could call this one bromo three chloro well when all things are equal like the numbers would be the same one in three is equivalent to one and three then I choose the number that would be the least for the highest alphabetical order so this would be one bromo three chloro cyclohexane so now let's go up to some more challenging problems here we have an amine so we would name this methyl amine
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here we have another amine now just like the other I you pack rules we find the longest carbon chain and name that so this would be propane but because we have this amine group and we would call this carbon 1 this would be pro pan amine and this would be a 1 propane amine but what do we do with this methyl substituent well we would call that methyl substituent in n methyl the capital
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n indicates that the methyl is on the nitrogen so this would be n methyl 1 propane amine now here we have a compound that has two different functional groups we have an alkene so we have a double bond and we have this aldehyde now typically when we would name an alkene we would put E and E as opposed to a any for an alkane and then when we have an aldehyde we would add the Al so which functional group is going to get the ending well the answer is the most oxidized in order to tell
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what the most oxidized is the most oxidized is going to have the the most oxidized carbon is the one that has the fewest carbon hydrogen bonds so we're looking for the most carbon oxygen bonds so the aldehyde is going to be the most oxidized so we would look at this as a now I can't write a Hexen al if we if we didn't have this double bond now again that aldehyde group is a terminal group so we don't need a number for it but we do need to account for this double bond so to account
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for that double bond I need to change this a n for the aim ending to an en and this time I need to give it a number and that number is going to be 2 because it starts at carbon 2 so this would be called hex to een al so the next one we have a bromine and an alcohol we have four carbons which would name it Butte tan all o L is an alcohol group the alcohol group is at carbon 2 so this would be a 2 Butte an all the bromine group is at carbon 3 so it would be 3 bromo to butan
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now a common question I get is is it all isn't it also correct to call it to bromo 3 butanol because the bromo comes first in the alphabetical order and the answer is no the functional group takes precedence and the alcohol is more oxidized than the bromine therefore it takes precedent now for this one we still have to find our longest carbon chain that contains the most substituents and or
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functional groups and here it is a cyclohexane or it's a cyclohexene so cyclo hex een and now we need to number to decrease the number of substituents and functional groups so if I call this carbon 1 then this substituent and the double bond starts at carbon 1 now a thing to note with double bonds around site cyclic molecules the double bond is defined as being between carbons 1 & 2 so there are only two ways that you can number this you can number it the
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way I have above when the blue numbers or you could number it this way now obviously if you number at the that I have on the inside then the substituents are at two and six and that's much bigger than three one and three so we would go with the outside numbers I'm just going to erase those briefly so we have one and three now we have a methyl at three so this would be a three methyl and it would be a one ethyl alphabetical order the ethyl comes first so this would be one
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ethyl three methyl cyclohexene again because that double bond is defined as being between carbons one and two you shouldn't need a number there if you would like to be thorough you may put a number there I'm not going to count you wrong for that the next compound again find your longest carbon chain when you have a terminal functional group your terminal functional groups is your you've got the aldehyde this is the carboxylic acid what's another term terminal functional group
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and a mean not an amine and an amide when you have the carbonyl carbon with the nitrogen next door that's an amen' that's a terminal functional group those are don't need to have number signifiers identifying where they are so here we have a four carbon chain with a carboxylic acid at the end so we wouldn't name this butane but because of that carboxylic acid I'm going to erase the e and add
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a wick acid so this is butanoic acid then I need to name my other functional group as a substituent in alcohol when it is a substituent is called hydroxy so this would be three hydroxy butanoic acid here we have two functional groups let me see if I can give this a highlight so here's a carbon carbon carbon carbon carbon now I'm going to number this so that the functional groups numbers are decreased there are five carbons here if I went the way then the double bond
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would still start at carbon three but the alcohol group would be on carbon 5 so that wouldn't make any sense now the alcohol group is more oxidized than the double bond so it's going to get the ending so we're going to start this with pentane all if it was an alkane that's what it would be called but because we have this double bond that starts at carbon 2 I'm going to expand this just
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a little bit and this would be a pentene all and I have to indicate this is where it starts to get a little bit tricky so I have to indicate where these substituents are so at carbon 1 I have the all and at carbon 2 I have the een and it's a pent so I would start by calling this pent 2 N 1 all now I need to name this substituent so this is a 2 chloro pent 2 een 1 all here one that's a little bit easier we have two carbons here I'm going to start
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numbering it with the alcohol group so we would call this ethanol and this is a one-eighth '''l to bromo and here we have a longest carbon chain we have an aldehyde group so 1 2 3 4 5 6 carbons so we would call that hex an au this is carbon one so this is 4 & 5 we have a 4 chloro and a 5 hydroxy and that's going to be the alphabetical order because C comes before H so this would be 4 chloro 5 hydroxy Hexen al
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