REACTIONS Flashcards
Draw out the mechanism for halohydrin formation
refer to notes
product of dihydroxylation
vicinal diols aka glycol (alcohol attachments on adjacent carbons)
What factor determines the rate of SN1 reactions?
electronics- the stability of the carbocation
hydroboration/oxidation of alkynes is markov? non markov?
non markovnikov
What happens to stereochemistry in an SN1 reaction?
stereochemistry is lost (since there’s a 50-50 chance of the Nu attaching to a particular side) and so you must draw both enantiomers or indicate that the product is a racemic mixture
reagents of free radical halogenation of alkanes
Br2or Cl2 and heat or light
product of dissolving metal reduction
alkene
reagents of catalytic hydrogenation with lindlar’s catalyst
H2
Pd poisoned with Pb
halogenation of alkynes results in syn? anti?
anti
Draw out the mechanism for hydroboration/oxidation of alkynes
refer to notess
What happens to stereochemistry in an SN2 reaction?
stereochemistry is inverted
What factor largely determines the rate of SN2 reactions?
steric hindrance
product of hydrohalogenation of alkenes
haloalkane
products of acid-catalyzed hydration of alkynes
enol and ketone
What reaction is acid-catalyzed hydration of alkynes analogous to?
oxymercuration of alkenes
Are 3° haloalkanes are more likely to react by SN1 or SN2? YYY
SN1; 3° haloalkanes make very stable carbocations and are protected from backside attack, preventing SN2
What 3 reactions form haloalkanes (an alkane with one halogen attachment)?
hydrohalogenation of alkenes, HBR addition to alkenes under radical conditions, and free radical halogenation of alkanes
intermediate of allylic bromination
allyl radical
product of catalytic hydrogentation with lindlar’s catalyst
alkene
Draw out the mechanism for oxymercuration/reduction.
refer to notes
Oxymercuration/reduction results in anti? syn? addition
anti
Which of the 3 reactions that form alcohols is carbocation rearrangement/1,2 hydride shifts possible?
acid-catalyzed hydration of alkenes
What happens in an SN2 reaction?
Nu attacks from the backside; bond between carbon and Lv breaks and bond between carbon and Nu forms at the same time
hydroboration/oxidation is Markov? non Markov?
non non non nan nan nan nan
halogenation of alkenes results in syn? anti?
anti
intermediate of halogenation of alkynes
bridged halogen ion
intermediate of oxymercuration/reduction
bridged mercurinium ion
Draw the transition state of an SN2 reaction.
refer to notes
Draw out the mechanism of acid-catalyzed hydration of alkynes
refer to notes
product of acid-catalyzed hydration of alkenes
alcohols
products of hydroboration/oxidation of alkynes
internal alkynes: ketone and enol
terminal alkynes: aldehyde and enol
Why is an SN2 reaction called so?
because both the Nu and the Lv ae involved in the rate determining step
List carbocations from least stable to most stable (for SN1 considerations)
methyl < 1° alkyl < 2° alkyl, 1° allylic, 1° benzylic < 3° alkyl, 2° allylic, 2° benzylic < 3° allylic, 3°benzylic
reagents of oxymercuration/reduction
- Hg(OAc)2, H2O
- NaBH4
intermeidate in halogenation of alkenes
bridged halogen ion
reagents of allylic bromination
NBS, light
reagents of hydroboration/oxidation of alkynes
- BH3, THF (or (sia)2BH if you just want one hydroboration step)
- H2O2, NaOH
product(s) of oxymercuration/reduction
alcohols
Which of the 3 reactions that form alcohols is non-Markovnikov?
hydroboration/oxidation of alkenes
Free radical halogenation of alkanes is regioselective in the order ___ and ___ is more regioselective than ___.
3°>2°>1°
chlorine
bromine
Draw out the mechanism for free radical halogenation of alkanes
refer to notes
intermediate of hydrohalogenation of alkynes
vinylic carbocation (positive charge on one of the carbons of a carbon-carbon double bond)
reagents of ozonolysis
- O3
- (CH3)2S aka DMS
Oxymercuration/reduction is markov?antimarkov?
markov
product of catalytic hydrogenation of alkenes and alkynes
alkanes
What 3 reactions form aldehydes and ketones?
ozonolysis, acid-catalyzed hydration of alkynes, and hydroboration/oxidation of alkynes
acid-catalyzed hydration is Markov or non-Markov?
Markovnikov
What 3 reactions form alcohols?
hydroboration/oxidation of alkenes, acid-catalyzed hydration of alkenes, oxymercuration/reduction
catalytic hydrogenation with linlar catalst results in syn? anti? addition
syn
Draw out the mechanism for hydrohalogenation of alkenes
refer to notes
product of hydrohalogenation of alkynes
haloalkene with halogen on more substituted carbon
geminal dihaloalkane, with 2 halogen atoms on the most substituted carbon
draw out the mechanism for dissolving metal reduction
refer to the book cuz you never wrote it down
Draw out the mechanism for dihydroxylation
refer to notes
product of halogenation of alkynes
1 mole of molecular halogen = vicinal dihaloalkene
2 moles of molecular halogen = vicinal tetrahaloalkane
In halohydrin formation, OH goes on the ___ carbon, and X2 goes on the ___ carbon.
more substituted
What are the 2 ways to form alkenes?
dissolving metal reduction, catalytic hydrogenation with lindlar catalyst
dihydroxylation results in syn? anti?
syn
reagents of acid-catalyzed hydration of alkenes
H2O and H2SO4
reagents of hydroboration/oxidaation
- BH3
- H2O2, NaOH
intermediate that forms in acid-catalyzed hydration of alkenes
carbocation
dissolving metal reduction results in syn? anti? addition
anti additon of hydrogens
reagents of acid-catalyzed hydration of alkynes
H2O, H2SO4, HgSO4
What are the 2 reactions that form alkynes?
alkylation of acetylide anions, dehydrohalogenation
reagents of dissolving metal reduction
2Na
NH3
reagents of hydrohalogenation of alkynes
2 mol HBr
intermediate of hydrohalogenation of alkenes
carbocation intermediate; rearrangements are possible
product of halogenation of alkenes
vicinal dihaloalkanes
hydroboration/oxidation of alkynes results in syn? anti?
syn
halohydrin formation results in syn? anti? addition
anti addition
reagents of halogenation of alkenes
X2, CH2Cl2
Draw out the mechanism for ozonolysis
refer to notes
Draw out the mechanism of acid-catalyzed hydration of alkenes.
refer to notes
Draw out the mechanism for the hydrohalogenation of alkynes
refer to notes
hydrohalogenation of alkynes is markov? non markov?
Markovnikov
product of free radical halogenation of alkanes
haloalkanes
Which of the 3 reactions that form alcohols is Markovnikov?
acid-catalyzed hydration of alkenes, oxymercuration/reduction
Which of the 3 reactions that form alcohols forms a racemic mixture?
hydroboration/oxidation of alkenes, oxymercuration/reduction
acid-catalyzed hydration of terminal alkynes is markov? anti markov?
markovnikov
product of ozonolysis
carbon-carbon double bond is cleaved and an oxygen bandaid is put on each wound
intermediates of acid-catalyzed hydration of alkynes
bridged mercurinium ion
Catalytic hydrogenation results in syn? anti? addition
syn
reagents of halogenation of alkynes
2 mol X2, CH2Cl2
intermediates of ozonolysis
molozonoide, which rearranges to ozonoide
Draw out the mechanism for allylic bromination.
refer to notesss
product of hydroboration/oxidation of alkenes
alcohols
Why is an SN1 reaction called so?
because only 1 species- the haloalkane- is involved in the rate determining step
Draw out the mechansim for hydroboration/oxidation of alkenes.
refer to notes
reagents of halohydrin formation
X2, H2O
draw out the mechanism for the halogenation of alkynes
refer to notes
reagents of hydrohalogenation of alkenes
HX
hydrohalogenation of alkenes is markov? or non-markov?
markovnikov
hydroboration/oxidation results in syn? anti? addition
syn, since C-B and C-H bonds form simultaneously
reagents of dihydroxylation
- OsO4
- NaHSO3/H2O
reagents of catalytic hydrogenation of alkenes and alkynes
H2
Pd, Pt, Ni, some metal catalyst
2 mol of H2 if starting from an alkyne
What happens in an SN1 reaction?
bond between C and Lv is broken completely
carbocation intermediate is formed and molecule becomes trigonal planar
Nu attacks from either side
racemic mixture is formed
Draw out the mechanism for halogenation of alkenes
refer to notes
intermediate of halohydrin formation
bridged halogen ion