Kaplan MCAT Orgo Review, CH 1 (Nomenclature)

Will the MCAT ever ask you to name a compound?

No, Kaplan says no.

How might MCAT test orgo then?

give you IUPAC name of reactant

answers will show products

need to know rxn

IUPAC stands for

International Union of Pure and Applied Chemistry

parent chain

longest chain find it

keep substitution and double and triple bonds in mind and fxnl group priorities

If no fxnl group priorities number parent chain so that

first substituent has lowest carbon number possible

the more oxidized a carbon is

the higher priority it has in the molecule

how does carbon oxidation state increase

with more bonds to heteroatoms

heteroatoms

atoms besides carbon and hydrogen

how does carbon oxidation state decrease

with more bonds to hydrogen

if there is a tie between double and triple bond location which takes priority>

double bond

this is only if they would have same number, if one is closer to start of parent chain you choose that one whether it is triple or double

substituents

fxnl groups that are not part of the parent chain

the highest priority fxnl group does what

determines the suffix for the compound and must be part of the parent chain

prefix n- means what

normal

a straight chain alkane substituent

you don't always have to say it

CH3- as a sub would be

methyl

CH3CH2- as sub would be

ethyl

CH3CH2CH2- as sub would be

propyl

or n-propyl (the other alkane subs mentioned could've been n- too)

what do the following subs look like:

isopropyl

isobutyl

sec-butyl

tert-butyl

what does neopentyl look like

prefixes and ABC order rule

di, tri, tetra..., tert, n-, sec- (all IGNORED) ABC by part after prefix

non-hyphenated roots are part of ABC order: iso, neo, cyclo (ALL MUST BE CONSIDERED)

hydrocarbons

compounds that contain only carbon and hydrogen atoms

alcohols are denoted by the presence of

-OH, which lends additional reactivity to the molecule

alkanes

what

general formula

single bond alkanes

CnH(2n+2)

alkanes 1-12 carbon names

methane 1

ethane 2

propane 3

butane 4

pentane 5

hexane 6

heptane 7

octane 8

nonane 9

decane 10

undecane 11

dodecane 12

alkyl halides

compounds with halogen substituents

4 common halogen prefixes

fluoro-

chloro-

bromo-

iodo-

-ene means

alkene

double bond(s)

-yne means

alkyne

triple bond(s)

name compound in image

1,3-butadiene

how do you know there is an alcohol by name

it ends in -ol

how to number and name when there is an alcohol

the carbon attached to the hydroxyl group gets the lowest possible number

alcohol vs bonds for naming

alcohol takes priority over double and triple bonds

what does hydroxy- mean

it means there is an alcohol present and it is not the highest priority substituent

hept-6-en-1-ol image

what does ethyl alcohol look like and other names

ethanol

drinking alcohol

isopropyl alcohol

look like

other names

2-propanol

propan-2-ol

isopropanol

what is a diol

another name too

aka glycol

alcohols with 2 hydroxyl groups

how do you indicate a diol/glycol

the suffix -diol and the numbering of each alcohol

ex: ethane-1,2-diol

what is ethylene glycol

ethane-1,2-diol

NOT an alkene!

what is a geminal diol

diols with hydroxyl groups on the same carbon

also called hydrates

not common

what is a vinicial diol

diols with hydroxyl groups on adjacent carbons

what are hydrates and are they common?

geminal diols

NOT common bc they spontaneously dehydrate (lose a water molecule) to produce carbonyl compounds with the functional group C=O

geminal vs vicinal mnemonic

geminal diols are like gemini, twins, on SAME carbon, like from same mom

vicinal diols sounds like vicinity which means adjacent carbons

what is a carbonyl group

a carbon double bonded to an oxygen

aldehydes

structures with a carbonyl group at one end (really it is C1 in the chain)

ketones

carbon double bonded to oxygen in the middle of a chain

naming aldehydes

generally the carbonyl carbon is C1

suffix becomes -al

when carbonyl is a position 1, which is usually, you do not need to include the numbered position of the carbonyl group

what does butanal look like?

what is methanal's common name

formaldehyde

what is ethanal's common name

acetaldehyde

what is propanal's common name

propionaldehyde

naming ketones

you almost always have to assign a number to the keton bc it is in the middle somewhere (except for propanone where it is assumed at C2 by default)

suffix will be -one

give ketone carbonyl highest priority unless it is trumped by another fxnl group

how may an ketone be names in none IUPAC

by listing the alkyl groups in ABC order then writing ketone

ex: ethylmethylketone

what does acetone look like and why is it special

it is the smallest ketone possible and it is weird bc "act-" usually refers to two carbons but here it is a 3 carbon compound

what does 2-pentanone look like

what does propanone look like and what are 3 other names for it

2-propanone

acetone

dimethylketone

what does 3-butene-2-one look like and what is its common name

methylvinylketone

what does 3-(5-oxohexyl)cyclohexanone look like

what does oxo- mean

there is either a ketone or an aldehyde in the structure that does not take the highest priority

what does keto- mean

there is a ketone that does not take highest priority (does not apply suffix -one) so you can use this or oxo-

alpha vs beta vs gamma carbon on diagram in reference to a carbonyl carbon

ex: the carbons on both sides of a ketone group are alpha carbons

ketones and aldehydes vs alcohols and double bonds for numbering

ketones and aldehydes take preference over both alcohols and double bonds

carboxylic acids

contain both a carbonyl group (C=O) and a hydroxyl group (-OH) on a terminal carbon

numbering carboxylic acids

C1 since it is the most oxidized functional group that will appear on the MCAT

you do not say the number for the carboxylic acid in the name bc position is assumed

what is the only scenario where a carbon is more oxidized than in a carboxylic acid situation

carbon dioxide (4 bonds from C to heteroatoms, the oxygen atoms, whereas only 3 in carboxylic acid)

naming carboxylic acids

always as a suffix since always highest priority

-oic acid

methanoic acid

appearance and common name

formic acid

ethanoic acid

appearance and common name

acetic acid

propanoic acid

appearance and common name

propionic acid

3 types of carboxylic acid derivatives

esters

amines

anhydrides

esters

carboxylic acid derivative

the hydroxyl group (-OH) of the carboxylic acid is replaced with an alkoxy group (-OR) where R is any hydrocarbon chain

alkoxy group

-OR

where R is any hydrocarbon chain

how to name an ester

the first part is the alkyl group of the -OR

the second part is the parent acid with the suffix -oate (count the carbonyl carbon as part of the parent chain)

ex: butyl methanoate

ex: ethyl propanoate

what would form if you exposed formic acid to butanol under the right conditions

butyl methanoate

what would ethyl propanoate look like

amides

carboxylic acid derivative

the hydroxyl group of the carboxylic acid is replaced by an amino group (a nitrogen containing group)

naming amides

suffix is -amide

substituents attached to the nitrogen are labeled N- (no numbers)

then named similarly to esters

what does N-ethyl-N-methylbutanamide look like

how to name amide that has two of the same groups hanging off the N

N,N-dimethylethanamide

how to name amide that has only H hanging off the N

propanamide (or change based on parent chain) this is just example for this one

anhydrides

carboxylic acid derivative

forms when two carboxylic acid molecules combine and one water molecule is removed

many anhydrides are ________, which may result from

cyclic

which may result from the intramolecular dehydration of dicarboxylic acid

how to name anhydrides

- if the anhydride is formed from only one TYPE of carboxylic acid, then take the carboxylic acid name (-oic acid) and drop acid, it is now -oic anhydride

ex: ethanoic anhydride

-if the anhydride is formed from two types of carboxylic acids (aka NOT symmetrical) both carboxylic acids are named (without the suffix acid) before anhydride is added to the name

ex: ethanoic propanoic anhydride

name this anhydride on other side

an- as a prefix generally means

not

so anhydride means without water, this is how you should remember that a water is removed during anhydride formation

in nomenclature,

use the suffix if

use the prefix if

suffix for the sub that is highest priority

prefix for all other subs

substituent priority list for only the fxnl groups on the MCAT

never miss easy points by quickly answering the wrong abc order

never do it

acetic anhydride is a common name for

ethanoic anhydride

methyl formate is a common name for

methyl methanoate

what common name prefix suggests aldehydes and carboxylic acids with only one carbon

form-