CSUMB
ESSP 311 Organic Chemistry I
Ronald W. Rinehart, Ph.D.
Table of Alkene Addition Reactions
Yes, Virginia, you need to know this stuff!
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Reaction name	reagents needed	product	regioselectivity	stereoselectivity	comments
catalytic hydrogenation	H₂ @ ~200 atm Pt, Pd, Rh, or Ni	corresponding (cyclo)alkane	------	syn addition to unhindered face	used to convert oils to saturated fats; incomplete rxn leads to formation of trans-unsaturated fat [not good!]
electrophilic HX addition	HI, HBr, HCl, HF	saturated (mono)halide	Markovnikov H⁺ to less subst end of C=C	none; planar carbocation intermediate	X- can add to either face of C⁺
free-radical addition of HBr	HBr (anh) organic peroxides R-O-O-R’	saturated (mono)bromide	anti-Markovnikov Br∙ to less subst end of C=C	none; planar carbon radical intermediate	gives an important alternative to normal HBr addition in devising synthetic sequences
addition of sulfuric acid	conc H₂SO₄	alkyl monohydrogen sulfate alkylsulfuric acid	Markovnikov H⁺ to less subst end of C=C	none; planar carbocation intermediate	product can be hydrolyzed in hot H₂O to yield alcohols; mixture of products due to carbocation rearrangements;
acid-catalyzed hydration	50% H₂SO₄ heat	alcohol	Markovnikov H⁺ to less subst end of C=C	none; planar carbocation intermediate	mixture of products due to carbocation rearrangements; only useful with H₂C=CH₂ RHC=CH₂ RHC=CHR’
oxymercuration- demercuration	1. Hg(OAc)₂ 2. NaBH₄, OH⁻	alcohol	Markovnikov H⁺ to less subst end of C=C	OH anti to H	no rearrangement
hydroboration- oxidation	1. B₂H₆ in THF (or diglyme) 2. H₂O₂, OH⁻	alcohol	anti-Markovnikov OH to less subst end of C=C	syn addition of H, OH	gives an important alternative to normal hydration in devising synthetic sequences
halogen addition	Cl₂ or Br₂ in nonpolar solvents	vicinal dihalide	-------	anti addition	cyclic halonium intermediate decolorization of Br₂ is common qualitative test for alkenes or C=C
halohydrin formation	Cl₂ or Br₂ in H₂O	vicinal halohydrin	Markovnikov X⁺ to less subst end of C=C	anti addition	cyclic halonium intermediate
epoxidation	peroxyacids RCO₃H	epoxide	-------	syn addition	epoxides can also be made by treating halohydrins with base
ozonolysis	1. O₃ 2. Zn, H₂O	C=C cleavage yielding aldehydes and/or ketones	-------	-------	useful for structural analysis Zn prevents oxidation of aldehyde product
permanganate cleavage	warm conc KMnO₄	C=C cleavage yielding ketones and/or carboxylic acids	--------	--------	useful for structural analysis aldehyde product oxidized to RCO₂H decolorization of purple KMnO₄ and formation of black MnO₂ ppt is qualitative test for C=C
syn-hydroxylation	cold dil KMnO₄ OR 1. OsO4 2. H₂O₂	vicinal diol	--------	syn addition	anti-hydroxylation is obtained when an epoxide is treated with OH⁻
cationic polymerization	H⁺	dimers, trimers, …	Markovnikov H⁺ to less subst end of C=C	none; planar carbocation intermediate	seen with gem-disubst, trisubst and tetrasubst C=C mixture of products due to carbocation rearrangements
free-radical polymerization	organic peroxides R-O-O-R’	long-chain polymers	head-to-head or head-to-tail	depends on catalyst	of extreme industrial, economic, and environmental importance