- WELCOME TO HYDROCARBONS PART THREE.
IN THIS VIDEO TUTORIAL
WE'LL FOCUS ON IUPAC NOMENCLATURE OF ALKANES,
ALKENES, ALKYNES, AND BENZENES.
LET'S GET STARTED.
ALL RIGHTY.
SO IUPAC, IF YOU'RE WONDERING WHAT THAT STANDS FOR,
IT'S AN INTERNATIONAL ORGANIZATION
THAT GOES BY INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY.
AND THIS IS THE GROUP OF PEOPLE THAT HAVE MADE UP
AND CREATED THE RULES THAT WE'RE GOING TO LEARN TODAY
FOR NAMING HYDROCARBONS.
SO HYDROCARBON IS VERY LITERAL.
IT MEANS THAT THE ONLY ELEMENTS PRESENT IN THE COMPOUND
ARE CARBON AND HYDROGEN.
NOW, ALKANES, THIS IS WHERE WE HAVE ALL CARBON-CARBON
SINGLE BONDS.
ALKENES, WE'RE GOING TO HAVE
AT LEAST ONE CARBON-CARBON DOUBLE BOND.
ALKYNES, WE'LL HAVE AT LEAST ONE CARBON-CARBON TRIPLE BOND.
AND THEN AROMATIC COMPOUNDS OR ARENES,
WE WILL FOCUS ON BENZENE
WHICH IS A SIX CARBON RING WITH ALTERNATING DOUBLE
AND TRIPLE BONDS.
SO WHEN WE DESCRIBE ALKANES,
WE HAVE THE MAXIMUM NUMBER OF HYDROGENS.
SO WE DESCRIBE ALKANES AS BEING SATURATED HYDROCARBONS
IN THE SAME WAY THAT A SATURATED SOLUTION
IS HOLDING THE MAXIMUM AMOUNT OF SOLUTE,
THE CARBONS ARE HOLDING THE MAXIMUM AMOUNT OF HYDROGENS.
AND SO WHEN WE LOOK AT THE CHEMICAL FORMULA OF AN ALKANE,
RIGHT, WE HAVE CNH2N+2.
WITH ALKENES, ALKYNES, AND AROMATICS,
WE HAVE LOST SOME OF THE HYDROGENS, RIGHT?
WITH AN ALKENE, IT'S CNH2N.
AND FOR ALKYNES, H2N-2, SO WE'VE LOST HYDROGENS.
SO WE DESCRIBE THOSE AS UNSATURATED.
AND YOU'LL HEAR THESE WORDS IN DESCRIBING FATS
AND THE HYDROCARBON TAILS OF FATS,
BEING SATURATED FATS OR UNSATURATED FATS.
SO WE WILL COME BACK TO THESE TERMS IN THE FUTURE, RIGHT?
AND THE MAIN THING IS WE H'S OUR LOST, RIGHT,
TO CREATE THE DOUBLE AND TRIPLE BONDS, RIGHT?
SINCE CARBON CAN ONLY HAVE FOUR BONDS,
IF IT'S CREATING DOUBLE AND TRIPLE BONDS,
IT LOSES ITS BONDS TO HYDROGEN. ALL RIGHTY.
SO NOW, WE'LL LOOK AT NAMES, THE NAMES HAVE THREE PARTS.
THE STRAIGHT CHAINS ARE NAMED USING THE ROOT NAMES
FROM THE HOMOLOGOUS SERIES.
THE ROOT NAME, I'LL ALSO DESCRIBE AS THE PARENT NAME.
WE CAN MAKE ALKANES INTO RINGS.
WHEN WE MAKE THEM INTO A RING,
WE'RE GOING TO PUT CYCLO IN THE FRONT TO INDICATE
THAT WE HAVE FORMED A RING.
AND THEN THE SUFFIX OF EACH NAME WILL TELL US
ABOUT THE TYPE OF BONDING.
SO WHEN WE HAVE ALL CARBON SINGLE BONDS, IT'S AN ANE.
WHEN WE HAVE AT LEAST ONE DOUBLE BOND, AN ALKENE.
AND IF THERE'S A TRIPLE BOND, WE WILL CALL IT ALKYNE.
SO THE SUFFIX OF EACH NAME TELLS US ABOUT THE TYPE OF BONDING
THAT OCCURS IN THE MOLECULE.
NOW, WE NEED TO LOOK MUCH CLOSER AT THE HOMOLOGOUS SERIES.
SO LET'S GO TO THE NEXT PAGE.
SO IN THIS NEXT PAGE--
NOW, THE HOMOLOGOUS SERIES IS MUCH LONGER THAN
WHAT I'VE SHOWN, BUT THIS IS ENOUGH FOR OUR PURPOSES.
THIS IS SOMETHING THAT YOU NEED TO MEMORIZE.
SO INITIALLY WE'LL ON THE SUFFIX NAMES,
BUT ONCE WE GET MORE COMPLICATED
WE WILL SEE THAT THE PARENT CAN HAVE BRANCHES
AND THEN WE'LL NEED TO BE AWARE OF THESE SUBSTITUENT NAMES.
SO NOTICE THE DIFFERENCE,
WHEN IT'S A SUFFIX NAME IT ENDS IN A AND E OR ANE OR YNE,
BUT WHEN IT'S A BRANCH IT ENDS IN YL. ALL RIGHT.
SO WHEN WE HAVE ONE CARBON IT'S METHANE, CH4.
IF WE HAVE A TWO CARBON CHAIN, IT'S ETHANE, CH3CH3.
OKAY, NOW, WE'RE GETTING TO A LONGER CARBON CHAIN
SO WE CAN BRING IN OUR SKELETAL LINE STRUCTURES, RIGHT?
A THREE CARBON CHAIN, PROPANE.
FOUR CARBONS, BUTANE.
FIVE CARBONS, PENT.
SIX IS HEX. IF YOU HAVE ANY LATIN OR LATIN--
IF YOU SPEAK OF LATIN-BASED LANGUAGE,
YOU'LL RECOGNIZE THESE NAMES.
HEPTANE IS SEVEN,
THERE'S OUR SEVEN CARBONS.
OCTANE FROM THE GOOD OLD OCTET RULE.
EVERYBODY SHOULD RECOGNIZE THE OCT FOR EIGHT. NON FOR NINE.
AND DEC FOR 10.
SO NOW THIS IS THE-- THEY'RE THE PARENT OR THE ROOT.
IF THEY'RE BRANCH, THEN THEY END IN THE YL.
AND FOR LACK OF A BETTER PLACE,
WE'RE GOING TO FOCUS ON THE IUPAC NAMES,
BUT THERE ARE SOME COMMON--
HERE'S A COMMON NAME OR REFERENCE
THAT I WANT YOU TO BE AWARE OF
BECAUSE IT TENDS TO SHOW UP IN BIOLOGICAL APPLICATIONS.
WHEN WE HAVE ONE CH2 GROUP, ALL RIGHT,
THIS MANY CH2 GROUPS IN THE MIDDLE OF A LONG CHAIN,
ONE OF THEM IS CALLED A METHYLENE GROUP.
TWO, RIGHT, WOULD BE ETHYLENE, AND THREE WOULD BE PROPYLENE.
AND THIS PATTERN COULD CONTINUE
BUT GENERALLY, YOU'LL SEE IT JUST IN A SMALL CARBON,
SOMETIMES THESE COMMON NAMES APPEAR AND SO IF YOU SEE THEM,
I DON'T WANT YOU TO GET THROWN BY THEM.
BUT THE MAIN EMPHASIS WOULD BE ON THE IUPAC NAMES
IN THE HOMOLOGOUS SERIES.
SO NOW LET'S LOOK AT NAMING THE SIMPLEST COMPOUNDS.
SOMETHING THAT'S A STRAIGHT CHAIN,
STRAIGHT CHAIN WITH NO BRANCHES.
ALL RIGHTY.
SO THE FIRST THING WE DO IS WE'RE GOING TO COUNT
THE CARBONS, RIGHT,
WE'RE GOING TO FIND THE ROOT OR THE PARENT
BY COUNTING THE CARBONS.
SO THAT'S WHERE THE HOMOLOGOUS SERIES COMES IN. ALL RIGHT.
AND THEN WE ASSIGN THE SUFFIX AND THE SUFFIX COMES, RIGHT?
IF THERE'S ALL SINGLE BONDS, ANE,
IF WE SEE A DOUBLE BOND, ENE, AND A TRIPLE BOND, YNE.
ALL RIGHT.
NOW, IF THERE IS A DOUBLE OR A TRIPLE BOND,
WE HAVE TO TELL EVERYBODY WHERE IT'S AT.
SO WE WILL PUT A LOCATOR NUMBER IN TO TELL EVERYBODY
WHERE THE DOUBLE AND THE TRIPLE BOND ARE.
IT'S IMPORTANT TO KNOW THAT WHEN WE'RE NUMBERING THE CHAIN,
WE WANT TO GIVE THE DOUBLE OR THE TRIPLE BOND,
THE LOWEST POSSIBLE NUMBER.
AND THEN FOR CYCLO ALKANES OR ALKENES,
REMEMBER THAT IT'S POSSIBLE TO HAVE A GEOMETRIC ISOMER
AND IF WE DO THEN WE WILL MAKE SURE TO ADD THAT TO THE NAME.
ALL RIGHTY. SO LET'S START--
I THINK IT'S EASIER TO START WITH A NAME AND DRAW STRUCTURE.
SO LET'S GET WARMED UP. NOTICE WHAT WE'RE GOING TO--
WE'RE LOOKING HERE AND WE SEE, OH, OKAY.
THERE'S AN ENE THAT TELLS US THERE'S A DOUBLE BOND
AND WE KNOW THAT DOUBLE BOND IS GOING TO COME OFF CARBON TWO.
HOW BIG IS OUR ROOT? HOW BIG IS OUR PARENT CHAIN?
THAT'S RIGHT HERE WITH THE HEX.
SO HEX IS SIX, SO WE'LL DRAW A SIX CARBON CHAIN. ALL RIGHTY.
SO THERE'S OUR SIX CARBON CHAIN, I'LL JUST ENABLE IT THERE,
SO WE'RE ALL TOGETHER
AND THEN WE KNOW THAT THERE IS A DOUBLE BOND
COMING OFF OF CARBON TWO, SO WE'LL PUT THAT RIGHT HERE.
SO TWO ATOMS ALWAYS SHARE THE DOUBLE BOND,
WE ONLY SAY THE LOWEST NUMBER.
AND THEN I LOOKED OUT HERE BECAUSE IT SAYS TRANS,
SO TRANS, WOULD TELL US THAT THEY'RE ACROSS THE DOUBLE BOND.
THIS TYPE OF TRANS CAN OFTEN BE TRICKY TO SEE.
WHEN WE FIRST LEARN IT,
IT'S VERY EXPLICITLY WRITTEN FOR US ACROSS THE DOUBLE BOND.
BUT THEN WHEN YOU SEE THEM IN YOUR TEXT MATERIAL,
IT'S ROTATED INTO THE PLANE OF THE PAPER. ALL RIGHTY.
LET'S TRY ANOTHER ONE.
SO THIS TIME WE NOTE, RIGHT, WE HAVE YNE AND THREE.
SO WE RECOGNIZE WE HAVE A TRIPLE BOND AND WITH THE OCT,
THERE'S OUR ROOT SO WE KNOW WE HAVE A EIGHT CARBON CHAIN.
AND I'LL PAY ATTENTION THIS TIME IT SAYS CIS.
SO I'M GOING TO START WITH THE DOUBLE BOND
AND I KNOW THE DOUBLE BOND
IS GOING TO START AT CARBON THREE AND THIS WILL CARBON FOUR.
WE NEED TO END UP WITH A EIGHT CARBON CHAIN.
SO CARBON TWO AND CARBON ONE.
SO ONE, TWO, THREE, FOUR, NOW CIS,
WE WANT TO BRING THIS DOWN SO THEY'RE ON THE SAME SIDE,
SO THAT WOULD BE CARBON FIVE, SIX, SEVEN, EIGHT,
LET ME WRITE THOSE OUT SO EVERYBODY SEES IT.
THERE WE GO. ALL RIGHT.
SO NOW WE HAVE CORRECTLY DRAWN THE STRUCTURE FOR CIS THREE--
OH, I MADE A MISTAKE, OCTYNE.
SO OCTYNE WOULD TELL US IT'S A TRIPLE BOND,
SO WE PUT A TRIPLE BOND HERE.
SO--AND SOMETIMES THIS IS HELPFUL TO DRAW THE ANGLES.
TECHNICALLY THIS IS LINEAR, SO THEN THERE SHOULDN'T BE ANY CIS.
OKAY, SO THAT WAS A BAD QUESTION,
WE CAN'T HAVE CIS IF WE HAVE AN ALKYNE, BUT THAT'S ALL RIGHT.
AND LET'S JUST REDRAW IT, ONE, TWO,
THERE'S OUR ONE, TWO, THREE, FOUR,
AND THEN FIVE, SIX, SEVEN, EIGHT.
SO ONE, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT.
MOST COMMONLY WITH ALKYNES, YOU'LL SEE IT STRAIGHT AWAY
BECAUSE OF THIS LINEAR ANGLE THERE. OKAY.
WELL, I THINK THAT ONE WILL BE ALL RIGHT.
LET'S KEEP GOING.
HERE WE SEE CYCLO, THAT TELLS US WE HAVE A RING
AND THEN ANE, ALL CARBON-CARBON SINGLE BONDS
AND THEN THE PENT TELLS US THAT WE WOULD HAVE FIVE CARBONS.
SO THIS IS A VERY SIMPLE ONE TO DRAW,
IT'S SIMPLY A PENTAGRAM, THAT WOULD BE CYCLOPENTANE.
ALL RIGHTY.
NOW, FOR THE MORE CHALLENGING PART.
LOOKING AT THE COMPOUND AND GIVING THE IUPAC NAME.
SO WE'LL GET WARMED UP WITH A PRETTY SIMPLE ONE,
WE SEE A RING, AS SOON AS WE SEE A RING
MAKE SURE TO WRITE CYCLO
AND THEN WE SIMPLY COUNT THE NUMBER OF CARBONS.
AND SO WE HAVE CYCLOHEXANE, ALL SINGLE BONDS. ALL RIGHTY.
NOW FOR THIS NEXT ONE, WE HAVE A DOUBLE BOND.
SO REMEMBER WE WANT TO NAME IT
TO GIVE THIS THE LOWEST POSSIBLE NUMBER.
SO, IN THIS CASE, WE'RE GOING TO NUMBER, LEFT TO RIGHT,
BECAUSE THAT GIVES US A TWO.
AND NOTICE IN THIS CASE, RIGHT THERE,
IT'S ACROSS THE DOUBLE BOND,
SO WE WOULD SAY TRANS TWO PENTENE,
REMEMBERING THAT THE TWO IS TELLING EVERYBODY
WHERE THE DOUBLE BOND OCCURS.
AND THEN THIS LAST EXAMPLE, OKAY.
WE HAVE ONE, TWO, THREE, FOUR,
SO IT'S IMPORTANT TO RECOGNIZE, RIGHT,
AS WE TRANSITION FROM A SINGLE BOND TO A TRIPLE BOND
THERE HAS TO BE AN ATOM THERE TO MAKE THAT CONNECTION.
AND SO THIS WOULD BE 2-BUTYNE,
WITH THE TWO TELLING EVERYBODY WHERE TO FIND THE TRIPLE BOND.
ALL RIGHTY.
SO NOW THAT WE HAVE THE BASICS DOWN,
LET'S LOOK WHAT HAPPENS WHEN OUR PARENT CHAIN HAS BRANCHES.
SO IN THIS--IN THIS TYPE OF COMPOUND,
WE ARE GOING TO LOOK FOR THE MAIN CHAIN,
WE'LL CALL THAT THE ROOT OR THE PARENT.
AND THAT'S THE LONGEST CONTINUOUS CARBON CHAIN.
ALL RIGHT.
AND THEN THE SUBSTITUENTS, THESE WILL BE THE BRANCHES, ALL RIGHT?
SO...
- JUST SLIP THAT DOWN JUST A LITTLE BIT.
JUST LOWER IT A LITTLE BIT, WE CAN'T SEE THE TOP.
- OH, THANK YOU. THERE WE GO, OKAY.
SO REMEMBER THAT OUR MAIN CHAIN WILL BE THE PARENT OR THE ROOT
AND THEN THE SUBSTITUENTS.
SO WITH SUBSTITUENTS, REMEMBER THAT THIS WILL BE THE, LIKE,
THE METHYL, RIGHT?
WE'LL USE THE YL TO INDICATE THAT IT'S A SUBSTITUENT.
ALL RIGHTY.
SO LET'S LOOK HERE.
FIND THE LONGEST CONTINUOUS CARBON CHAIN
AND ASSIGN THE ROOT NAME.
SO WHEN WE LOOK AT THIS MOLECULE HERE WE CAN FIND
ONE, TWO, THREE, FOUR, FIVE, SIX, SEVEN,
SO THERE'S OUR LONGEST CHAIN. ALL RIGHT.
SO THAT TELLS US THAT THE ROOT NAME WILL BE HEPTANE,
BECAUSE IT'S ALL SINGLE BONDS.
SO NOW--OKAY SO WE'VE ASSIGNED THE SUFFIX
THEN WE WANT TO LOOK AT THE BRANCHES,
BUT LET'S LOOK AT THE NUMBERING FIRST.
WE COULD NUMBER THIS LEFT TO RIGHT
OR WE COULD NUMBER RIGHT TO LEFT.
WHEN YOU'RE FIRST STARTING OUT,
THEN YOU PROBABLY WANT TO TRY TO NUMBER IN BOTH WAYS
AND THEN WE'LL FIGURE OUT WHICH NUMBERS ARE CORRECT.
SO LET'S FIND OUR BRANCHES, OKAY, RIGHT?
ASSIGNING A LOCATOR NUMBER TO ALL SUBSTITUENTS.
LET'S NAME THEM FIRST.
SO THERE'S A SUBSTITUENT, A SUBSTITUENT, AND A SUBSTITUENT.
SO ONE CARBON IS A METHYL.
ONE CARBON IS A METHYL AND TWO CARBONS IS AN ETHYL, ALL RIGHT.
SO WE'VE NAMED OUR SUBSTITUENTS. OKAY.
NOW, WE HAVE TO ASSIGN THE LOCATOR NUMBERS.
THIS IS HOW WE DECIDE,
SHOULD WE BE USING THE RED NUMBERS OR THE GREEN NUMBERS?
AND SO THERE ARE NO DOUBLE OR TRIPLE BONDS.
IF WE DID, THIS IS THE FIRST PRIORITY.
HOWEVER, FOR THIS MOLECULE,
WE DON'T HAVE ANY DOUBLE OR TRIPLE BONDS,
SO THEN WHAT WE DO IS WE WANT THE FIRST BRANCH
TO HAVE THE LOWEST POSSIBLE NUMBER.
SO IF WE LOOK AT THE RED NUMBERS, RIGHT,
THE FIRST BRANCH IS ON CARBON THREE.
IF WE LOOK AT--LET ME CIRCLE THAT SO EVERYONE CAN SEE IT.
IF WE LOOK AT THE GREEN NUMBERS,
NOTICE THAT THE FIRST BRANCH, RIGHT, IS ON CARBON TWO,
ALL RIGHT. SO THE GREEN NUMBERS WIN.
SO NOW WE WILL USE THE GREEN NUMBERS TO ASSEMBLE THE NAME.
WHEN WE HAVE MORE THAN METHYL GROUP,
WE WILL INDICATE THAT WITH A DI, A TRI, OR A TETRA.
SO SINCE WE HAVE TWO METHYL GROUPS
WE WOULD CALL THIS DIMETHYL, OKAY.
SO NOW LET'S PUT THIS ALL TOGETHER.
ONE LAST THING TO POINT OUT IS THAT THE SUBSTITUENTS,
WE GIVE THOSE AN ALPHABETICAL ORDER.
AND SO EVEN THOUGH IT'S DIMETHYL, WE WOULD USE THE M.
SO WE DON'T CONSIDER THE PREFIXES
AND THE ALPHABETIZATION.
SO E COMES BEFORE M.
LET'S PUT THIS NAME TOGETHER, ALL RIGHT.
SO THE ETHYL COMES FIRST
AND THE ETHYL IS COMING OFF OF CARBON FOUR.
SO WE SAY 4-ETHYL AND THEN WE HAVE TWO METHYL GROUPS.
SO THE METHYL GROUPS
ARE COMING OFF OF CARBON TWO AND CARBON FIVE.
SO 2, 5 DIMETHYL AND NOW WE FINALLY GET TO PUT HEPTANE.
SO NOTICE EVERY ATOM IN THE MOLECULE IS ACCOUNTED FOR
ALL ASPECTS OF THE STRUCTURE.
LET'S TRY ONE MORE TOGETHER.
ALL RIGHTY.
SO THE FIRST THING, RIGHT,
FIND THE LONGEST CONTINUOUS CARBON CHAIN
AND THEN WE HAVE TO DECIDE HOW TO NUMBER IT.
REMEMBER THE DOUBLE AND TRIPLE BONDS HAVE THE TOP PRIORITY
SO WE CAN LOOK AT THIS MOLECULE
AND SEE THE DOUBLE BOND IS CLOSER TO THE RIGHT.
SO WE'RE GOING TO WANT TO GO ONE, TWO, THREE, FOUR, FIVE,
SIX, SEVEN, EIGHT.
SO WE FOUND OUR LONGEST CONTINUOUS CARBON CHAIN
AND WE SEE THAT THERE'S A DOUBLE BOND COMING OFF OF CARBON THREE.
SO THAT WOULD BE 3-OCTENE.
THEN WE CAN LOOK AT OUR SUBSTITUENTS.
THIS TIME WE HAVE THREE METHYL GROUPS, ALL RIGHT.
SO THAT WOULD BE TRIMETHYL.
THEN WE HAVE TO TELL EVERYBODY WHERE THEY ARE.
SO THAT WOULD BE 5, 6, 7.
NOTICE THAT IF WE HAVE THREE NUMBERS HERE,
WE BETTER HAVE A TRY, RIGHT? THIS ALWAYS HAS TO MATCH.
AND THEN WHENEVER WE HAVE A CYCLOALKANE OR ALKENE,
REMEMBER THAT WE HAVE TO THINK ABOUT CIS OR TRANS.
IN THIS CASE WE LOOK AT THIS DOUBLE BOND
AND IT'S A TRANS DOUBLE BOND.
SO THE FULL NAME FOR THIS COMPOUND
IS TRANS 5, 6, 7 TRIMETHYL 3-OCTENE.
REMEMBERING THAT THE THREE IS TELLING US
WHERE TO FIND THE DOUBLE BOND.
ALL RIGHTY.
SO NOMENCLATURE CAN BE VERY CHALLENGING,
SO I THINK IT'S IMPORTANT
TO WORK SOME MORE PRACTICE PROBLEMS.
LET'S PRACTICE AGAIN.
THIS TIME THEN WE'LL START WITH WHAT I CONSIDER THE EASIER
OF THE TWO, WORKING FROM THE NAME.
SO IF WE LOOK AT THIS NAME, WE SEE HERE IS OUR ROOT.
WE KNOW WE HAVE A SIX CARBON CHAIN
AND WE SEE THAT THE-- THERE'S A DOUBLE BOND,
WE HAVE CARBON NUMBER TWO. SO--
AND WE SEE THAT IT'S CIS, ALL RIGHT.
SO THERE'S GOING TO BE OUR-- WE'LL PUT HERE AND THERE,
SO ONE, TWO, THREE, FOUR, FIVE, SIX.
SO LET ME NUMBER THAT FOR EVERYBODY, OKAY.
SO THE ROOT TOLD US-- HEX TOLD US SIX CARBONS.
WE KNOW TO PUT THE DOUBLE BOND AT CARBON TWO
AND THEN THE STEREO CHEMISTRY,
WE PUT THE ALCO BRANCHES ON THE SAME SIDE BECAUSE OF CIS.
AND THEN THE LAST PIECE HERE IS WE HAVE A SUBSTITUENT.
SO WE GO TO CARBON FOUR
AND WE ADD THE ETHYL GROUP, TWO CARBONS.
SO THERE WE HAVE--THERE WE GO.
THIS IS THE STRUCTURE FOR CIS, FOUR ETHYL, TWO HEXENE.
LET'S TRY ONE MORE. HERE WE HAVE CYCLOHEXENE.
SO WE'LL MAKE A SIX-MEMBERED RING
AND THEN WE NOTICE HERE IT SAYS TRANS,
SO WE'LL HAVE ONE WEDGE AND ONE DASH
TO SHOW THAT THE SUBSTITUENTS ARE ABOVE AND BELOW THE RING.
SO WE'LL JUST RANDOMLY PUT ONE, TWO, THREE, FOUR, FIVE, SIX.
WE CAN PUT THEM ANY ORDER THEY WANT, OKAY. ONE ETHYL.
SO I'LL MAKE THAT A WEDGE, RIGHT? AND THEN CH2, CH3.
AND THEN COMING OFF OF CARBON THREE,
WE'LL MAKE SURE THAT THAT'S A DASH, CH3, TO GIVE OUR TRANS.
SO THERE WE GO.
NOW, THE LITTLE BIT MORE CHALLENGING,
GIVEN THE STRUCTURE, WHAT IS THE NAME?
SO WHEN WE LOOK HERE, THIS ONE,
WE CAN GO ONE, TWO, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT.
THIS NUMBERING, NOTICE BOTH DIRECTIONS GIVE US A THREE,
BUT NUMBERING THIS WAY WE GET A THREE, FOUR
AS OPPOSED TO A THREE, FIVE.
SO WE'LL GO WITH THAT NUMBERING
AND THEN WE IDENTIFY ALL OF OUR SUBSTITUENTS.
SO THIS WOULD BE 3, 4, 5- TRIMETHYLOCTANE,
ALL RIGHTY. LET'S MOVE ON TO THE NEXT ONE.
AH, SO NOW WE HAVE A DOUBLE BOND
AND WE CAN LOOK AND SEE THAT ALL OF THE BRANCHES
ARE COMING OFF OF THE SAME SIDE.
SO WE KNOW THAT THIS COMPOUND WILL BE A CIS, ALL RIGHTY.
LET'S FIGURE OUT.
SO THE NUMBERING, WE WANT TO GIVE THE DOUBLE BOND
THE LOWEST POSSIBLE NUMBER.
SO WE KNOW TO START NUMBERING ON THE LEFT
AND THEN WE KEEP GOING TO FIND THE LONGEST CARBON CHAIN.
SO NOW, WE LOOK AT SEVEN.
SO WE RECOGNIZE THAT'S GOING TO BE HEPT
AND WE HAVE THE DOUBLE BOND SO THAT WILL BE HEPTENE
AND THE DOUBLE BOND STARTS AT CARBON TWO.
BUT BEFORE WE GET THERE, WE NEED TO LOOK AT THE SUBSTITUENTS.
REMEMBER THAT THESE SUBSTITUENTS ARE SIDED ALPHABETICALLY.
SO THIS ETHYL GROUP WILL BE SIDED BEFORE THE METHYL GROUP.
SO CIS-4-ETHYL-5-METHYL
AND THEN WE CAN BRING IN OUR PARENT OR ROOT 2-HEPTENE, RIGHT?
AND THE TWO IS TELLING EVERYBODY WHERE TO FIND THE DOUBLE BOND,
ALL RIGHT. ONE LAST ONE HERE.
SO WE CAN NUMBER, IT'S IN THE MIDDLE,
THE TRIPLE BOND'S IN THE MIDDLE.
SO WE CAN NUMBER FROM THE LEFT OR THE RIGHT,
WE'LL GET THE SAME RESULT.
AND WE HAVE OUR TWO METHYL SUBSTITUENTS.
SO IT WOULD BE 2, 5-DIMETHYL AND WITH OCTYNE OR WITH HEXYNE,
WITH ALKYNES, WE DON'T HAVE TO WORRY ABOUT CIS OR TRANS.
AND THEN WE TELL EVERYBODY, RIGHT, 3-HEXYNE.
SO THERE'S THE THREE TELLING EVERYBODY
WHERE TO FIND THE TRIPLE BOND. ALL RIGHTY.
SO THAT COVERS ALKANES, ALKENES, AND ALKYNES,
THEY HAVE A VERY SIMILAR NAMING STRATEGY
THAT WE PRACTICE TOGETHER.
LET'S BRIEFLY LOOK AT AROMATICS BENZENE RINGS.
WE--THIS IS NOT A HUGE EMPHASIS IN THE COURSE
BUT IT'S GOOD TO COVER IT
BECAUSE THERE'S A COUPLE IMPORTANT BENZENE DERIVATIVES.
SO--OH, OOPS THOSE ARE MY NOTES. HERE.
WE GOT A SNEAK PREVIEW OF WHAT'S GOING TO HAPPEN ON THIS PAGE,
ALL RIGHTY. SO ROOT NAMES.
SO IN MY CLASS WE'RE RESPONSIBLE FOR BENZENE.
REMEMBERING THAT THE ALTERNATING DOUBLE BONDS CAN BE SHOWN
OR YOU CAN WRITE A CIRCLE IN THE MIDDLE, RIGHT?
I ALSO WANT YOU TO REMEMBER THIS COMPOUND, THERE'S THE CH3 GROUP.
THAT'S TOLUENE.
AND WHEN WE PUT THE ALCOHOL GROUP ON THERE,
WE CALL THAT A PHENOL, ALL RIGHT.
SO THESE ARE THE THREE ROOT NAMES THAT YOU WANT TO KNOW.
SUBSTITUENTS WILL JUST FOCUS ON THAT--THE ALCO SUBSTITUENTS.
SO THOSE WILL ALL COME FROM THE HOMOLOGOUS SERIES, OKAY.
SO IF THERE'S MORE THAN ONE SUBSTITUENT PRESENT,
THEN WE GIVE THE SECOND SUBSTITUENT
THE LOWEST POSSIBLE NUMBER.
THE FIRST SUBSTITUENT ALWAYS IS GIVEN THE NUMBER ONE.
SO FOR TOLUENE OR PHENOL,
THE NUMBER ONE CARBON WOULD BE THE CARBON ON THE RING
THAT'S BONDED TO THE METHYL GROUP OR THE ALCOHOL GROUP.
AND THEN WE'RE GOING TO FOLLOW THE SAME PROCEDURE AS BEFORE
LISTING THE SUBSTITUENTS IN ALPHABETICAL ORDER
AND OF COURSE ALWAYS PROVIDING A LOCATOR NUMBER
SO THAT PEOPLE KNOW WHERE THEY'RE AT.
IF WE HAVE A LOT OF SUBSTITUENTS WE CAN USE THE PREFIXES
THAT WE LEARNED IN NAMING ALKANES, ALKENES, AND ALKYNES,
RIGHT.
SO THEN JUST TO EMPHASIZE, RIGHT,
MAKE SURE THAT YOU RECOGNIZE-- OOPS, TOLUENE AND PHENOL.
PHENOL IS VERY IMPORTANT.
IT WAS ONE OF THE ORIGINAL ANTISEPTICS
WHEN HUMAN BEINGS ACKNOWLEDGED GERM THEORY, OKAY.
SO--AND REMEMBER THE AROMATIC RINGS ARE THE ONE RING
THAT WE ARE ABLE TO WRITE IN A CONDENSED FORMULA.
SO WE'LL GET TO THAT IN THIS NEXT EXAMPLE, RIGHT?
SO DRAW THE SKELETAL LINE STRUCTURE FOR 3-PROPYLPHENOL,
RIGHT?
SO THE PHENOL TELLS US THIS AND THEN WE HAVE OUR DOUBLE BONDS.
SO THAT BECOMES CARBON ONE,
CARBON TWO, THREE, FOUR, FIVE, SIX.
SO THEN THE SECOND PART OF THE NAME SAYS
THAT COMING OFF OF CARBON THREE,
WE HAVE PROPYL WHICH YOU RECOGNIZE
AS A THREE CARBON CHAIN, SO ONE, TWO, THREE. OKAY.
SO THIS WOULD BE THE STRUCTURE OF 3-PROPYLPHENOL.
AND THEN OUR LAST EXAMPLE, C6H5.
WE WANT TO RECOGNIZE THAT AS THE BENZENE RING.
THIS IS THE C6H5, ALL RIGHT AND THEN THIS WILL BE THE BRANCH
OR THE SUBSTITUENT.
AND SINCE THERE'S ONLY ONE BRANCH WE DON'T WORRY ABOUT--
WE CAN GO ANYWHERE.
SO ONE, TWO, THREE, FOUR.
AND SO THAT WOULD BE--
SO NOW THAT WE HAVE THE STRUCTURE,
LET'S GIVE THE IUPAC NAME.
SO THIS WOULD BE BUTYLBENZENE.
SO THE BENZENE RING IS HERE
AND THEN THERE'S THE BRANCH COMING OFF. ALL RIGHTY.
SO WE'VE WORKED THROUGH QUITE A BIT OF NOMENCLATURE PRACTICE
AND THIS WOULD BE A GREAT TIME TO DIG INTO YOUR HOMEWORK
AND WORK A FEW PRACTICE PROBLEMS TO REINFORCE YOUR UNDERSTANDING.