prelim org chem lesson 4 Flashcards
a compound that contains an -OH
(hydroxyl) group bonded to a tetrahedral
carbon
alcohol
, CH3OH, is the simplest alcohol
Methanol
In the IUPAC system, a compound containing two hydroxyl groups is named as ____, one containing three hydroxyl groups as a __
diol, triol
We commonly refer to compounds containing hydroxyl groups on adjacent carbons as
glycols.
are polar molecules
Alcohols
are both polar covalent.
The C-O and O-H bonds
In the liquid state, alcohols associate by
hydrogen bonding.
are weak acids and react with NaOH and other strong bases to form water-soluble salts.
phenol
both contain an OH group.
Alcohols and phenols
weaker acids and do not react in this
manner.
Alcohols
elimination of a molecule of
water from adjacent carbon atoms gives an alkene.
Dehydration
is most often brought about by
heating an alcohol with either 85% H3PO4 or concentrated H2SO4
Dehydration
alcohols are the most difficult to dehydrate and require temperatures as high as 180°C.
1°
alcohols undergo acid-catalyzed dehydration at somewhat lower temperatures.
2°
alcohols generally undergo acid-catalyzed dehydration at temperatures only slightly above room temperature.
3°
large amounts of water favor alcohol formation, whereas removal of water from the equilibrium mixture
favors alkene formation.
Le Chatelier’s principle
are resistant to oxidation.
Tertiary alcohols
is an
oxygen atom bonded to two carbon
atoms.
ether
The simplest ether is
dimethyl ether
The most common ether is
diethyl ether.
an ether in which one of the
atoms in a ring is oxygen
Cyclic ether:
are also known by their
common names.
Cyclic ethers
is an important building block
for the organic chemical industry; it is also used as a fumigant in foodstuffs and textiles, and in hospitals to sterilize surgical instruments.
Ethylene oxide
is a useful laboratory and
industrial solvent.
Tetrahydrofuran
which
oxygen bears a partial negative charge
and each carbon bonded to it bears a
partial positive charge.
Ethers
have lower boiling points than
alcohols of the same molecular formula
Ethers
resemble hydrocarbons in their
resistance to chemical reaction.
Ethers
a compound containing an -SH
(sulfhydryl) group.
Thiol
The most outstanding property of low-
molecular-weight thiols is their stench.`
Thiols
They are responsible for smells such as those from rotten eggs and sewage
Thiols
The scent of skunks is due primarily to these two thiols.
Thiols
are derived in the same
manner as are the names of alcohols.
IUPAC name
ommon names for simple thiols are
derived by naming the alkyl group
bonded to -SH and adding the word
“mercaptan”`
show little association by hydrogen
bonding
Thiols
have lower boiling points and are less soluble in water and other polar solvents than alcohols of similar molecular weight.
Thiols
are weak acids (pKa 10), and are
comparable in strength to phenols.
Thiols
react with strong bases such as NaOH
to form water-soluble thiolate salts.
Thiols
The most common reaction of thiols in
biological systems is their oxidation to
disulfides, the functional group of which is a
disulfide (-S-S-) bond
are readily oxidized to disulfides by O2
Thiols
They are so susceptible to oxidation that they must be protected from contact with air during storage.
Thiols
