in this lesson we're gonna focus on naming alcohols so let's start with some basic examples so what is the name of ch3oh the common name for this molecule is methyl alcohol it's also called methanol now what about this one ch3 ch2 Oh H the common name for this alcohol is ethyl alcohol it's also known as ethanol now what about these two examples was the common name for this alcohol so this is known as isopropyl alcohol it has an isopropyl group attached to the Oh H group and this is called tert-butyl alcohol now let's go over the IU Pack nomenclature for these two alcohols so you can draw isopropyl alcohol like this if you want to and so if we number it this is gonna be one two three so the O H group is on carbon 2 and we have a three carbon chain so instead of saying propane it's gonna be propanol it's gonna have the suffix oh L and the Oh H group is on carbon 2 so this is called 2-propanol now let's focus on this example so I'm going to redraw our like this so we still have a three carbon chain but now we have the O H group on carbon 2 and also a methyl on carbon 2 so this is gonna be called 2 methyl - 2-propanol so that is the IU paganini for tert-butyl alcohol try this example go ahead and name the alcohol so we have to number it and so the O H group is on carbon 2 and we have a five carbon chain so instead of saying pentane it's gonna be Penton all but particularly to panel because of this now what if we have two hydroxyl groups how can we name the molecule in this case now for this example it really doesn't matter in which direction we count because no matter what direction we start from we're gonna get an H group at carbon three and carbon four so whenever you have two alcohols it's known as a dial so this is gonna be three four dash hexane because there are six carbons in the parent chain and then it's gonna be dial so three four hexane dial now let's move on to our next example go ahead and name the following molecule so which group should we give priority is it the alkyl halide or the alcohol the alcohol is the functional group that will contain the para name and it's gonna have more priority than the bromine atom so therefore we need to start counting in this direction starting from the alcohol so this is carbon one two three four five so we have a five carbon alcohol and so it's gonna be called pensando and the O H group is on carbon one so it's one Penton all and we have a bromine on carbon four so it's four bromo one pensa mo here's another example for you so this time we're going to have three substituents and it really doesn't matter which direction we start counting because the OAH group will be on carbon 3 however for these two substituents it doesn't matter if we count it from left to right we're gonna get the name to bromo - for chloro and then the OHS on 3 so that's gonna be 3 Penton all now let's say if we count it any other direction so I'm going to redraw this first we still need to put the substituents in alphabetical order so bromo will still come before chloro now this is gonna be for bromo - 2 - coral - repentant all so which name is the correct eye you pack name for this molecule now the first substituent if possible you want it to be the lower number so 2 is less than 4 so the first one wins you want to try to put the numbers in a Senate order after you alphabetize the substituents so it's going to be 2 Brummel for chloro 3 pence at all now what if you're given a condensed structure that looks like this what would you do to name it the first thing I would do is turn into a line structure so we have four carbons there which I'm going to write it like this and then on carbon one let's make this carbon one two three four on a carbon one we have an O age group and on carbon four we have a ch3 group so now how would you name it so this is a methoxy group on carbon 4 and we have a hydroxy group on carbon one whenever you have a hydroxy group and a methoxy group this is going to take priority and so this is going to be part of the parent name therefore instead of saying butane it's gonna be beautiful and the O age group is on carbon one so it's 1-butanol and we have a methoxy group from carbon four so it's four methoxy one beYOU know that what if we have an alcohol on a ring how can we name this molecule so we have a cyclopentane ring because there's a total of five carbon atoms but we don't have to say one cyclo penta no we don't really need to number we can simply say cyclo pentene all because there's only one substituent on a ring so it's automatically on carbon one now what if we have two substituents on a ring so let's say we have an ethyl group and the hydroxy group now in this case we need to number it this is going to be one two three four five and six however we don't have to say one cyclohexanol because the hydroxyl group is already part of a parent name and it's going to be on carbon one it's automatically assign that position so to name it this is going to be three ethyl cyclohexanol now we do need to specify that 3 on the ethyl group because the ethyl group can be on carbon 2 it could be on 4 and so we need to say hey this is on 3 we need to give enough information that if we're given the name we can draw this specific molecule now let's consider one more example with rings go ahead and name in this compound so automatically we know the Oh H is going to be on carbon 1 if we start counting this way it's going to give us very high numbers the methyl will be on 3 and the ethyl will be on 6 but if we count in the clockwise direction the ethyl group will be on carbon 2 and the methyl group will be on carbon 5 so 2 & 5 is less than 3 & 6 so we want to count it in that direction so to put it all together it's going to be two ethyl 5-methyl cyclohexanol and so that's it