Shared Flashcard Set

Details

Chapter 9: Alkynes: An Intro to Organic Synthesis
part of OCHEM Test 3
106
Organic Chemistry
Undergraduate 2
07/01/2017

Additional Organic Chemistry Flashcards

 


 

Cards

Term
the rules for naming alkynes are similar to those for naming alkenes, except...
Definition
-the suffix -yne is used for an alkyne
-compounds with both 2bl bonds and triple bonds are enynes
-when there is a choice in numbering, 2bl bonds receive lower numbers than triple bonds
-compounds can also contain alkynyl groups
Term
the suffix used for alkyne
Definition
-yne
Term
enynes
Definition
compounds with 2bl bonds and triple bonds
Term
when there is a choice in numbering, ______ bonds receive lower numbers than ______ bonds
Definition
double
triple
Term
alkynes can be prepared by ______ rxns of 1,2-dihalides, using strong base
Definition
elimination
Term
alkynes can be prepared by elimination rxns of ______, using strong base
Definition
1,2-dihalides
Term
alkynes can be prepared by elimination rxns of 1,2-dihalides, using ______
Definition
strong base
Term
the ______ used in the preparation of alkynes are formed by addition of X2 to alkenes
Definition
dihalides
Term
the dihalides used in the preparation of ______ are formed by addition of X2 to alkenes
Definition
alkynes
Term
the dihalides used in the preparation of alkynes are formed by ______ of X2 to alkenes
Definition
addition
Term
the dihalides used in the preparation of alkynes are formed by addition of ______ to alkenes
Definition
X2
Term
the dihalides used in the preparation of alkynes are formed by addition of X2 to ______
Definition
alkenes
Term
______ give alkynes when treated with a strong base
Definition
vinylic halides
Term
vinylic halides give ______ when treated with a strong base
Definition
alkynes
Term
vinylic halides give alkynes when treated with a ______
Definition
strong base
Term
alkyne triple bonds result from...
Definition
the overlap of 2 sp-hybridized C atoms
Term
the bonds formed in an alkyne triple bond
Definition
1 sigma bond and 2 pi bonds
Term
the strongest C-C bond
Definition
triple bond
Term
alkynes are somewhat (more or less) reactive than alkenes in electrophilic addition rxns
Definition
less
Term
alkynes are somewhat less reactive than alkenes in ______ rxns
Definition
electrophilic addition
Term
HX and X2 add to alkynes by...
Definition
an electrophilic addition mechanism
Term
how HX and X2 add to alkynes by an electrophilic addition mechanism
Definition
-addition of 2 equivalents of HX occurs if the acid is in excess
-addition occurs with Makovnikov regiochemistry and trans stereochemistry
Term
when HX and X2 add to alkynes, addition of ______ of HX occurs if the acid is in excess
Definition
2 equivalents
Term
when HX and X2 add to alkynes, addition of 2 equivalents of ______ occurs if the acid is in excess
Definition
HX or X2
Term
when HX and X2 add to alkynes, addition of 2 equivalents of HX occurs if the ______ is in excess
Definition
acid
Term
when HX and X2 add to alkynes, addition of 2 equivalents of HX occurs if the acid is in ______
Definition
excess
Term
when HX and X2 add to alkynes, addition occurs with ______ regiochemistry and trans stereochemistry
Definition
Makovnikov
Term
when HX and X2 add to alkynes, addition occurs with Makovnikov regiochemistry and ______ stereochemistry
Definition
trans
Term
the intermediate of ______ to alkynes is a vinylic carbocation, which forms less readily than an alkyl carbocation
Definition
addition of HX or X2
Term
the intermediate of addition of HX or X2 to ______ is a vinylic carbocation, which forms less readily than an alkyl carbocation
Definition
alkynes
Term
the intermediate of addition of HX or X2 to alkynes is ______, which forms less readily than an alkyl carbocation
Definition
a vinylic carbocation
Term
the intermediate of addition of HX or X2 to alkynes is a vinylic carbocation, which forms (more or less) readily than an alkyl carbocation
Definition
less
Term
the intermediate of addition of HX or X2 to alkynes is a vinylic carbocation, which forms less readily than ______
Definition
an alkyl carbocation
Term
some types of hydration rxns of alkynes
Definition
-Hg(II)-catalyzed additions
-hydroboration/oxidation of alkenes
Term
in Hg(II)-catalyzed additions of ______, the -OH group adds to the more substituted C to give Markovnikov product
Definition
alkynes
Term
in Hg(II)-catalyzed additions of alkynes, the ______ adds to the more substituted C to give Markovnikov product
Definition
-OH group
Term
in Hg(II)-catalyzed additions of alkynes, the -OH group adds to ______ to give Markovnikov product
Definition
the more substituted C
Term
in Hg(II)-catalyzed additions of alkynes, the -OH group adds to the more substituted C to give ______
Definition
Markovnikov product
Term
in Hg(II)-catalyzed additions of alkynes, the intermediate ______ product tautomerizes to a ketone
Definition
enol
Term
in Hg(II)-catalyzed additions of alkynes, the intermediate enol product ______ to a ketone
Definition
tautomerizes
Term
in Hg(II)-catalyzed additions of alkynes, the intermediate enol product tautomerizes to ______
Definition
a ketone
Term
the mechanism in Hg(II)-catalyzed additions to alkynes is similar to that of addition to alkenes, but...
Definition
no NaBH4 is necessary for removal of Hg
Term
the products formed from an internal alkyne
Definition
mixture of products
Term
the products formed from a terminal alkyne
Definition
a methyl ketone
Term
hydroboration /oxidation of alkynes gives an intermediate ______ product that tautomerizes to a carbonyl product
Definition
enol
Term
hydroboration /oxidation of alkynes gives an intermediate enol product that ______ to a carbonyl product
Definition
tautomerizes
Term
hydroboration /oxidation of alkynes gives an intermediate enol product that tautomerizes to ______ product
Definition
a carbonyl
Term
______ of a terminal alkyne gives an aldehyde
Definition
hydroboration
Term
hydroboration of ______ gives an aldehyde
Definition
a terminal alkyne
Term
hydroboration of a terminal alkyne gives ______
Definition
an aldehyde
Term
______ of an internal alkyne gives a ketone
Definition
hydroboration
Term
hydroboration of ______ gives a ketone
Definition
an internal alkyne
Term
hydroboration of an internal alkyne gives ______
Definition
a ketone
Term
______ is complementary to Hg(II)-catalyzed hydration
Definition
hydroboration/oxidation
Term
hydroboration/oxidation is ______ to Hg(II)-catalyzed hydration
Definition
complementary
Term
hydroboration/oxidation is complementary to ______
Definition
Hg(II)-catalyzed hydration
Term
complete reduction of an alkyne to an alkane occurs when...
Definition
H2/Pd is used
Term
partial reduction of an alkyne to ______ occurs with H2 and a Lindlar catalyst
Definition
a cis alkene
Term
partial reduction of an alkyne to a cis alkene occurs with ______ and ______
Definition
H2 a Lindlar catalyst
Term
partial reduction of an alkyne with ______ in ______ produces a trans alkene
Definition
Li NH3
Term
partial reduction of an alkyne with Li in NH3 produces ______
Definition
a trans alkene
Term
partial reduction of an alkyne proceeds through ______ --> vynilic radical --> vinylic anion
Definition
an anion radical
Term
partial reduction of an alkyne proceeds through an anion radical --> ______ --> vinylic anion
Definition
vynilic radical
Term
partial reduction of an alkyne proceeds through an anion radical --> vynilic radical --> ______
Definition
vinylic anion
Term
the product of the partial reduction of alkynes
Definition
a more stable trans vinylic anion
Term
______ cleave alkyne bonds to produce carboxylic acids or CO2 (terminal alkyne)
Definition
O3 or KMnO4
Term
O3 or KMnO4 cleave ______ to produce carboxylic acids or CO2 (terminal alkyne)
Definition
alkyne bonds
Term
O3 or KMnO4 cleave alkyne bonds to produce ______
Definition
carboxylic acids or CO2 (terminal alkyne)
Term
oxidative cleavage rxns were formerly used for...
Definition
structure determinations
Term
acidity of terminal alkynes
Definition
weakly acidic (pKa = 25)
Term
______ (-NH2) can deprotenate a terminal alkyne, yielding an acetylide anion
Definition
very strong bases
Term
very strong bases (______) can deprotenate a terminal alkyne, yielding an acetylide anion
Definition
-NH2
Term
very strong bases (-NH2) can ______ a terminal alkyne, yielding an acetylide anion
Definition
deprotenate
Term
very strong bases (-NH2) can deprotenate ______, yielding an acetylide anion
Definition
a terminal alkyne
Term
very strong bases (-NH2) can deprotenate a terminal alkyne, yielding ______
Definition
an acetylide anion
Term
acetylide anions are stabilized by...
Definition
the large amount of "s character" of the orbital that holds the electron
Term
acetylide anions are strongly (electrophilic or nucleophilic)
Definition
nucleophilic
Term
______ can react with haloalkanes to form substitution products
Definition
acetylide anions
Term
acetylide anions can react with ______ to form substitution products
Definition
haloalkanes
Term
acetylide anions can react with haloalkanes to form ______
Definition
substitution products
Term
alkylation rxn
Definition
nucleophilic acetylide anion attacking the electrophilic C of the haloalkene
Term
in ______, the nucleophilic acetylide anion attacks the electrophilic C of haloalkane to produce a new alkyne
Definition
an alkylation rxn
Term
in an alkylation rxn, the ______ attacks the electrophilic C of haloalkane to produce a new alkyne
Definition
nucleophilic acetylide anion
Term
in an alkylation rxn, the nucleophilic acetylide anion attacks the ______ to produce a new alkyne
Definition
electrophilic C of haloalkane
Term
in an alkylation rxn, the nucleophilic acetylide anion attacks the electrophilic C of haloalkane to produce ______
Definition
a new alkyne
Term
______ can form an alkylation proiduct
Definition
any terminal alkyne
Term
______ are limited to primary alkyl bromides and iodides
Definition
acetylide alkylations
Term
acetylide alkylations are limited to...
Definition
primary alkyl bromides and iodides
Term
______ cause dehydrohalogenation rxns with secondary and tertiary halides
Definition
acetylide ions
Term
acetylide ions cause ______ with secondary and tertiary halides
Definition
dehydrohalogenation rxns
Term
acetylide ions cause dehydrohalogenation rxns with ______
Definition
secondary and tertiary halides
Term
strategies for organic synthesis
Definition
work backward from the structure of the product, but keep the structure of the starting material in mind
Term
general depiction of an alkyne
Definition
-C≡C-
Term
what has higher priority, alkyne or phenyl?
Definition
aklyne; phenyl is just a substituent
Term
[image]
Definition
ketone
Term
ketone
Definition
[image]
Term
[image]
Definition
enol

alkene and alcohol
Term
enol
Definition
[image]

alkene and alcohol
Term
stability of enols
Definition
not very stable
Term
since enols aren't very stable, they tend to turn into...
Definition
ketones and aldehydes
Term
[image]
Definition
aldehyde
Term
aldehyde
Definition
[image]
Term
why alkynes tend to be more acidic than alkynes
Definition
because of the stability and electronegativity of sp C
Term
we figure out the sdtructure of then alkyne that yielded the products based on...
Definition
the oxidation states of specific C's
Term
whyb hydrogenation of an alkyne to yield an alkene would yield a cis isomer
Definition
because it's syn addition
Term
poisoned catalyst
Definition
catalyst that has had something put on it to make it less active
Supporting users have an ad free experience!