functional groups and reacitons Flashcards
hydrocarbon properties
low boiling point compared to other functional groups
only intermoleculare force is londen dispersion
do highly branched alkanes have higher or lower boiling points
lower because stacking is less efficient
alkyl halides
C-X where c is carbon chain and X is a halogen
alkyl halide formation reaction
- hydrohalogenation
- substitution rxn with OH-x
are halogens a good leaving group
yes, which makes alkyl haides good reactive subjects for substitution and elimiation
good leaving groups
weak bases that want to accept electrons, do not want to share e-
- conjugate base of a strong acid
good nulceophiles
want to donate electrons
have increased negative charge
increased bacisty from right to left
hydrogenation
reduction of alkenes to alkanes with h2 and a calayst
phenols
aromatic ring with an alcohol group attatched
ortho
position of substituents on aromatic ring where the are adjacent
para
position of substituents on aromatic ring where they are on opposite sides
meta
position of substituents on aromatic ring seperated by a carbon
what effect does adding an OH group to a benzene ring have on the boiling point
rasises it because of h bonding
pKa of OH
weakly acidic with pKa of 15
- less acidic than phenols beacuse resonance
phenol pKa
10
- acidity can be increased by EWG
- acidicty decreased by EDG
pcc
weak oxidizing agent
primary or secondary oh into a carbonyl
NaCr2O7
strong oxidizaing agent
covert primary oh into COOH
convert secondary OH into ketone
K2Cr2O7
strong oxidizaing agent
covert primary oh into COOH
convert secondary OH into ketone
CrO3
strong oxidizaing agent
covert primary oh into COOH
convert secondary OH into ketone
ubiquinone Q
cownzyme Q, electron acceptor between c 1,2,3,
silyl esters
Si-O bond forms with OH group to protect it from reagent and is removed by fl-
mesylates
react OH with methyl sulfonyl chloride to protect oh group
tosylates
react oh with tosyl suflonyl chloride to protect oh group
how to protect carbonyls during reactions
form acetals with an equivalent diol which is then removed under acidic conidtion
LiALH4
strong reducing agent: reduces both COOH and carbonyls to alcohols
hemiacetals
intermediate in the formation of acetals where there is one OH group in replacement of one to the OR groups
aceteal
an aldehyde has 2 OR groups
what structure is responsible for acetals and hemiaceltas
aldehydes
what structure is assoicated with ketals and hemiketals
ketones
hemiketal
one of the 2 OR group s of. a ketal is replaced with OH
ketal
ketone is replaced by R1, R2, OR1, OR2
aldehyde
terminal carbonyl group
ketone
carbonyl is within the molecule
boiling points of aldehydes, COOH, and OH in order from lowest to highest
C=O<OH< COOH
intermolecular interactions that aldehydes have which alkanes do not
dipole dipole
which has a higher melting point? OH or aldehyde
OH because of hydrogen bonding
alpha hydrogen
the hydrogen adjacent to the carbonyl carbon
- important for ketone and aldehyd ereactions because of resonance stability
pka of aldehyde/ ketone
17-19
which is more acidic? aldehydes or ketones
aldehydes are slightly more acidic than ketones
do aldehydes and ketones act as nulceophiles or electrophiles
both
which part of aldehyde can act as an electrophile
the carbonyl carbon has a partial positive
which part of the aldehyde can act as a nucleophile
the carbanion with negative charge
which of the two are more reactive and why between aldehydes adn ketones
aldehydes because less steric hinderance
what happens when an aldehyde is reacted with PCC
nothing , weak oxidizing agent
strong oxiidizing agents
Na2CO2O7, K2Cr2O7, CrO3, KmNO4, Ag2O, H2O2
can a ketone be oxidized by a strong oxidizing agent?
no
NaBH4
weak reducing agent
reaction with water and aldehyde
nucleophile: water
electrophile: carbonyl carbon
product: geminal diol on carbonyl –> hydration
reaction with alchol and aldehyde
nucleophile: R-OH
electrophile: carbonyl carbon
product: hemiacetal (would be hemiketal in ketone)
reation with hydride (NaBH4 or LiAlH4) and aldehyde
aldehyde is reduced to a primary alochol
reaction with amide and aldehyde
amide is nucleophile
attacks carbonyl carbon and produces imine –> enamine
keto form
c=o
enol form
c=c with oh instead of o
kinetically favored enolate
formed more quickly and less stable
- db tends to invovle less substituted carbon because of less hinderance
- low temp
thermodynamic enolate
db forms between carbonyl carbon and more substituted carbon , slower and more stable
aldol condensation
aldehydes and ketones can react with eacother
- nucleophilic enolate and electrophilic carbocation
- molecules join and produce an aldol (aldehyde/ketone + alcohol).
aldol elimination
when the aldol OH is removed via elimination to produce double bond
retroaldol reaction
aldol can be reversed back into aldehyde and ketone at high temperatures
carboxylic acid derivatives
COOH where OH is replaced by something else
- amides, esters, anhydrides
physical properties of carboxylic acids are determined by what
ability to hydrogen bond
-IMF stronger than alcohols
pKa of COOH
4
saponification
basic conditions
carboxylic acids are deprotinated and their conjugate bases form salts
ROOH+ NA+ +.OH- –> RCOO - + h2o
amides
COOH deriviatives where the OH group is replaced with an amine
lactims
cyclic amides
beta lactams importance
form antibiotics like penicillen and its deriviatives
ester
COOH deriviative where OH is replaced by OR
longer chain recieves oate ending
is the boiling point of an ester higher or lower than a COOH
lower because less ability to hydrogen bond
acid annhydrides
COOH derivative formed by two cooh combined,
often symmetric
DIBAL
reducing agent that reduces COOH to aldehyde
NaBH4 reaction with COOH
nothing
LiAlH4 reaciton with cooh
primary alcohol
decarboxylation reactions
when high temperature is applied to a dicarboxylic acid, one of them is lost as CO2
example PDC complex
function of PDC complex
removes co2 from pyruvate to make acetyl coA
decarboxylation steps of TCA cycle
isocitrate –> alpha ketogluterate
alpha ketogluterate –> succinyl coA
cooh reaction reference
has great leaving group (OH) and undergoes nucleophilic substitution
fisher esterification
when ROH acts as a nucleophile and attacks carbonyl of COOH
- nucleophilic substitution
Hell-Volhard-Zelinsky halogenation
COOH is halogenated at the alpha carbon because of its slight acidity
regarding the relative interconversion of COOH derivitives order them most to least reactive
annhydrides> esters> amides
higher reactive can be converted into lower reactive but not vice versa
transesterification
when an ester reacts with a new ROH group that is different from its own and gets a new ROH substituent attatched to carbonyl carbon
hydrolysis of amides
convert amide to parent cooh and amine
- break down of peptide bonds via hydrolysis
electronic effect
EWG like oxygen make a carbonyl carbon more reactive
- resonance stabilizes charge and increases acidity
amines
derivatives of NH3
- undergo hydrogen bonding
- higher h bonding ability than aldehyde so higher bp
analine
benzene with an amine substituent
imines
characterized by c=n bond and 1 c-c bond
enamines
like the enol form of carbonyls with oxygen
1 c-n bond and 1 c=c bond
relationship between enamines and imines
they are tautomers and interconvert
amides
COOH derivative with NH replacing OH
thiol group
R-SH
sulfides/ thioethers
R-S-R’ group similar to ethers w oxygen
thioester
R-CO-s-r’
- acetyl coA
disulfides
R-S-S-R
how does resonance affect acidity
increases it
what affects impact reactivity
EWG, steric hinderance, strain, resonance
how does angle strain (like in a lactam) affect reactivity
increases
