Part 3 Flashcards
is there any metabolic reaction possible on a carbon carbon triple bond?
YES
direct oxidation on carbon carbon triple bond
is there any oxidation possible on a carbon nitrogen triple bond?
NO, only in the case of an alpha carbon attached to the carbon nitrogen triple bond
what is a “ketene”?
which reaction produces a ketene as an intermediate?
R-C=C=O
direct oxidation of carbon carbon triple bond after the falling apart of the hypothetical oxidative intermediate
ketene reacts with water to produce a carboxylic acid
explain the metabolic reaction that Carbon Carbon triple bond undergoes
direct oxidation on carbon carbon triple bond.
oxidation produces a hypothetical very unstable intermediate. Hydride shifts to the left and C=O is formed to produce a KETENE.
when this ketene undergoes reaction with water, it produces the corresponding carboxylic acid
what compounds can undergo N-hydroxylation?
is this an oxidation or reduction?
-aromatic amides
-barbiturates
-others
on a barbiturate, how many possible N-hydroxylations are possible?
2 are possible, but it’s likely that only 1 will be hydroxylated, because the whole purpose of phase 1 is to just put a polar functional group on the molecule for phase 2 to occur
give a potential formula for an aromatic amide
AR-NH-COOH
what does zero with a slash through it symbolize
an aromatic ring
AR-NH2
what reaction is possible?
N-hydroxylation on either (or both, but not likely) Hydrogens
AR-NH2
what is an important consideration with this reaction?
if the aromatic ring happens to be a fused system (2 or more rings) it gives enough stability to a nitrenium intermediate (AR-N+-H) which is a potent carcinogen
HOWEVER this is not likely with just 1 ring (phenyl)
what is aniline
aromatic ring with NH2 as the only substituent
what phase 1 metabolic reactions are possible on a carbon-carbon double bond?
C=C is a known place of oxidation between carbons
cis-olefin undergoes epoxidation (oxidation) to produce cis-epoxide. similarly, trans-olefin undergoes epoxidation (oxidation) to produce trans-epoxide.
These are stable enough to not undergo a hydride shift, but they are chemically reactive so we don’t want them floating around for too long
the epoxide can undergo epoxy hydrase (a hydrolysis reaction) to produce a DIOL which is reasonably stable
how is it that when cis-olefin and trans-olefin are oxidized, you still get cis and trans epoxides, respectively?
there is no time for the intermediate to rotate, so the positions remain the same
when is a “dihydroxy metabolite” produced?
through oxidation of a C=C and then hydrolysis reaction on the formed epoxide.
produces a diol with 2 hydroxyl groups
what is a olefin group? what is another name for it
aka vinyl group
C=C
between….
cyanohydrin
carbinolamine
ketene
the postulated oxidative product of the oxidation of carbon-carbon triple bonds
which is the most unstable?
ketene and postulated product are the MOST unstable.
postulated product is probably the most unstable
what are “Arenes”
same thing as an aromatic hydrocarbon. basically just an aromatic ring
do aromatic systems undergo oxidation?
YES - ends in phenol formation
- arene oxide formation can be intercepted and stabilized or go to phenol formation
(2. Arene oxide hydrase (epoxy hydrase) - dihydrodiol dehydrogenase)
- phenol formation
is methoxy electron donating or withdrawing?
OCH3
Electron donating
if there are 2 electron withdrawing R substituents on an aromatic ring, is ring hydroxylation to phenol more or less likely?
LESS LIKELY
the more electron donating, the more likely ring hydroxylation will take place
besides the ring itself, what is another likely place for hydroxylation in a structure with an aromatic ring?
at the BENZYLIC CARBON
