Mechanisms Flashcards
Hydrohalogenation
HX across double bond, halo at mark
Hydrohalo with HOOH
Halo at less sub
Acid catalyzed hydration
H2O across double bond in presence of an acid- OH at mark
Oxy demurc
OH at mark, HgOAC at anti mark which is removed. Requires NABH4 to take Hg off, replacing it with H
Hydroboration oxidation
Uses BG3/THF, then H2O2 and NAOH. OH at anti mark, H at mark
Catalytic hydration
Syn addition of H2 across db- Uses H2 and PT.
Halo and halohydrin
Halogen added (anti and enantiomers) across DB
If halohydrins are done in nucleophilic solvents
Nucleophiles may be added
Anti-dihydroxylation
OH added at both ends of ethylene =
Epoxide
Done with peracid (acid with acidic -ooh group)- used to make epoxides
Syn dihydroxylation
OsO4/Ox agent (or KMnO4 and NaOH, cold, dilute) creates syn addn of OH
Oxidative cleavage
Cutting db in hald (with o3 and DMS for ozonolysis or KMnO4 and concentration heat for permaganatecleavage)
________ eliminates halo from anti mark, ________ adds it to mark
NaOMe, HBr
Halogen and water
Anti and enantiomer- OH at mark, halo at anti mark
mCPBA and H3O+
Anti and enantiomer addition of OH across DB
D2 and Pd
Syn addition of O across DB and enantiomer
H+ and H2O
OH at mark
EtOH at oxy demurc
OEt substitutes
Elimination for alkynes
Strong base just leaves r groups- (-) charged base attacks H, electrons move to other H and then halogen, taking it off. Repeat.
NaNH2 and NH3, then H2O
Take off H and halogen (may add more bonds)
H2 and Pt or Pd
Catalytic hydration- Gets rid of extra bonds
How to stop H2 from taking off all bonds?
Poisoned (Lindlar’s catalyst)
Na and NH3
Takes 1 bond off
