Final Flashcards
(15 cards)
Alkene + strong Bronsted HX acid
Electrophilic addition of HX to alkenes
Alkene –> alkyl halide
Markovnikov
Alkene + water + acid catalyst
Acid-catalyzed hydration
Alkene –> alcohol
H-OH addition
Markovnikov
Carbocation intermediate
Rearrangement possible
Alkene + HBr + peroxides (ROOR)
Radical addition of HBr to alkenes
anti-Markovnikov
no rearrangement
Alkene + Hg(OAg2), then NaBH4 in H2O
Oxymercuration/demercuration
alkene –> alcohol
cyclic intermediate
no rearrangement
Markovnikov
Alkene + Hg(OAg2), then NaBH4 in alcohol
Alkoxymercuration/demercuration
alkene –> ether
same as oxymercuration/demercuration, except alcohol is solvent
Alkene + BH3 THF, then H2O2 + HO-
hydroboration/oxidation
H/OH addition
anti-Markovnikov
syn addition
Alkene + X2 + CCl4 or CH2Cl2
Halogen addition
X2 addition
trans addition
no carbocation formation, no rearrangement
Alkene + X2 + H2O
Halohydrin formation
alkene –> halohydrin
X/OH addition
same mechanism as halogen addition
water is nucleophile
trans addition
Alkene + peracid (ROOOH, R=CH3, tBu, CF3)
Epoxidation of alkenes
alkene –> epoxide
Syn addition
Alkene + R-COOOH + acid catalyst + H2O
Antidehydroxylation by epoxide opening
Alkene –> trans diol
OH/OH addition
SN2-like mechanism
trans addition
Alkene + OsO4 + H2O2
Syn dihydroxylation
alkene –> cis diol
OH/OH addition
syn addition
Alkene + KMnO4 + OH-
Syn dihydroxylation
alkene –> cis diol
OH/OH addition
syn addition
Alkene + H2 + transition metal catalyst (Pd/C or Pt or Ni)
Hydrogenation of alkenes
Alkene –> alkane
H/H addition
syn addition
Alkene + O3 + Me2S
Ozonolysis
Alkene –> C=O and aldehyde/ketone
cleaves C=C bond
Alkene + KMnO4 + H2O, warm and concentrated
Permanganate cleavage
alkene –> carboxylic acid
cleaves C=C bond
