Terms in this set (92)
molecules possessing unpaired electrons
homolytic bond cleavage is what kind of process?
the reverse reaction is what kind of process?
Homolytic bond dissociation energies
energies required to break covalent bonds homolytically
Least stable to most stable energy required to break bonds
3prime > 2prime > 1prime
3 steps in radical substitution
1. chain initiating
2. chain propagating
3. chain terminating
radicals are created to start reaction
Heat or UV light cause the weak halogen bond to undergo homolytic bond cleavage
radicals react to form other radicals
left over radicals combine randomly
Ground state oxygen is a ____.
In biological systems, O2 is an e' ____.
In immune systems, what is O2 radical used for?
to kill pathogens
What is the reason for the smell of rancid fat?
Flavinoids in wine
low antioxidant value
rapidly metabolized and excreted
atoms other than carbon or hydrogen
activates longevity-related protein SIRT-1
improves insulin sensitivity
similar effects to calorie restriction
improves mitochondria function
only stable structure with OH on a double bond
nomenclature of ethers
name alkyl groups on O and follow w/ "ether"
for more complex structures name ethers as alkoxy groups on the longest C chain
Compare the boiling points of alcohols to ethers and why
Alcohols have higher boiling points than ethers because of H bonding
Hydration of alkenes
alkene ---> Markovnikov alcohol
follows carbocation mechanism - can rearrange
oxymercuration - demercuration
alkene --> Markovnikov alcohol
1) Hg(OAc)2, H2O
hydrocarboration - oxidation
alkene --> anti-Markovnikov alcohol
Concerted syn addition
4 centered transition state
cleavage of a chemical bond by acids
Reactions of alcohols
1. OH Bond cleavage
2. CO Bond cleavage
Alcohols are (strong/weak) (acids/bases)
(poor leaving group)
RO- is a ____
(OMs) contain functional group -SO3CH3, which is derived from methanesulfonic acid
(OTs) contain the functional group -SO3C6H4CH3, which is derived from toluenesulfonic acid
Since OH- is a poor leaving group:
convert to OMs or OTs and then displace with a nucleophile
Amine (Et3) is a (weak/strong) (acid/base)
If deltaH is negative
If delta H is positive
change in enthalpy
both reactive sites are on the same molecule
What is indicated when asking for systematic nomenclature?
Nu:- + RCH2OH ------>
If the reaction Nu:- + RCH2OH ----->
is converted to NU:- + RCH2OMs ----->
RCH2O- + NuH
RCH2Nu + -OMs
" + -OTs
C-O Bond cleavage
1. dehydration of alcohols
2. formation of alkyl halides from alcohols
HCl reacts with 3prime ROH by what kind of mechanism?
SN2 (same as HBR)
What is required for HCl to react with 1prime and 2prime?
Lewis Acid (ZnCl2)
Reaction with PBr3 and SOCl2 requires what types of alcohols?
1prime, 2prime, NOT 3prime
Intramolecular dehydration of 1prime ROH results in what kind of ethers?
Williamson ether synthesis results in what kind of ethers?
what are t-butyl ethers used for in organic synthesis?
block a reactive functional group while a reaction is carried out on another part of the compound
Ethers with 1prime and 2prime alkyl groups can be cleaved with:
HI or HBr
conjugate base of an alcohol
an oxirane. 3 membered cyclic ethers containing one oxygen and two carbon atoms
preparation of epoxide by reaction of alkenes with peracids
peroxide (OOH) is part of structure
reactions of epoxides
strain makes epoxides very reactive
epoxides undergo ring opening under both acid and base conditions
in symmetrical cases, acids and bases conditions result in opposite regeoselectivity
What is an important structural component of many functional groups?
Relates carbonyl compounds to alcohols
a reaction that increases H content
-requires oxidizing agent
a reaction that decreases H content and increases O content
-requires oxidizing agent
lithium aluminum hydride
will reduce any functional group
Order of reduction to RCH2OH by LiAlH4 from easiest to hardest
aldehyde > ketone > ester > acid
reacts like LiAlH4 with aldehydes and ketones but
esters and acids
pyridinium chlorochromate (PCC)
Oxidizes primary alcohols into aldehydes
Oxidizes secondary alcohols into ketones
H2CrO4, H2CrO3, in aqueous acetone
Na2Cr2O7 in H2SO4
oxidizes primary ROH to acids, secondary ROH to ketones
What is required to oxidize tertiary ROH?
there must be at least 1H on the OH carbon
DMSO, (COCl)2 / EtN -60C
primary ROH -> aldehyde
secondary ROH -> ketone
tertiary ROH -> no reaction
compounds containing carbon-metal bonding that ranges from ionic to covalent
Metal intermediates between ionic and covalent
organolithium (most useful)
organomagnesium and organolithium
stable in ether solvents
-more reactive due to strain
-react with water in presence of acid catalyst to form diols
Restrictions on Grignard reagents
Grignards are strong bases/strong nucleophiles and are incompatible with:
-C triple bond C-H
C triple bond N
Conjugated unsaturated systems
compounds with alternating = and - bonds or p orbital adjacent to pi bond
CH2 = CH - CH3
Ph - CH3
NBS is a source of reactive bromine. It is most often used for allylic/benzylic bromination and in the formation of halohydrines from alkenes.
a process of reasoning backward from a target molecule to a suitable set of starting materials
A reaction, like the Diels-Alder reaction, in which two connected groups add to the end of a pi system to generate a new ring
a reaction that yields only one constitutional isomer as the product when two or more constitutional isomers are possible products
hydrogen will add to the least substituted carbon of the double bond
a twisted shape or position
H atom bonds to the C with most Hs
hydrogen atom bonds to an alkene or alkyne at the carbon having the few hydrogen atoms