Organic Chemistry Reactions substituted carbon addition carbon 1 Alkene halogenation more stable carbocation 1 2 methyl hydride shift most 2 Alkene hydration conversion to an alcohol via acid catalytic addition on most substituted 3 Alkoxylation of an alkene by addition of a nucleophile like methanol other than water or a halogen ether product on most stable carbocation by subsequent deprotonation 4 Dihalogenation of cyclic alkene halonium ion leading to attack from above below resulting in trans configuration addition in a diastereospecific but racemic manner 5 Hypohalous acid addition to alkenes halogen on least substituted carbon with positive charge and diol added to the most substituted most stable carbocation 6 Alkene hydroboration alkylborane on the least substituted carbon due to steric hindrance reaction with hydroxide and peroxide forms an alcohol by replacement BH2 OH rationalized by the complex transition state without an intermediate ether solvent a Dislamylborane and 9 BBN are more selective borane units providing greater selectivity due to increased steric hindrance by mass regioselectivity OH replacement 7 Oxymercuration of an alkene addition of HgOAc mercury on least substituted carbon most stable carbocation OH addition by reaction with NaBH4 removal of Hg back donation by the d orbital a Alkoxymercuration uses an alcohol solvent rather than water leading to an ether from EtOH to OEt by subsequent deprotonation 8 Permanganate hydroxylation of alkenes concerted 1 3 dipolar cycloaddition forming a manganate ester five membered ring that leads to a cis diol with addition of water and OH 9 Osmylation hydroxylation of alkenes formation of an osmate ester ring by OsO4 leads to a cis diol in a diastereospecific racemic mix catalytic NMO regenerates OsO4 10 Epoxidation of alkenes reaction with peroxyacid CH3CO3H yields oxirane and carboxylic acid in a diastereospecific racemic mixture by a complex transition state cis configuration 11 Ozonolysis of alkenes forms an ozonide rearrangement after 1 3 dipolar cycloaddition yields an initial 1 2 3 trioxolane addition of H2O2 gives a ketone and carboxylic acid while addition of H3CSCH3 sulfur derivative gives a ketone and aldehyde 2 products for both 12 Alkyne halogenation more stable carbocation no rearrangement due to pi bond most substituted carbon addition of the halogen with retention of the double bond E Z four products 13 Alkyne hydration acid catalyzed nucleophilic addition of water to the most stable carbocation deprotonation leads to an enol that undergoes keto enol tautomerization 14 Oxymercuration of an alkyne mercury is lost when the enol is formed leading to keto enol tautomerization to give a ketone product NABH4 is not needed in this reaction just strong acid like H2SO4 15 Alkyne hydroboration less sterically hindered product on the less substituted carbon without a carbocation leading to replacement of boron with OH giving an enol which tautomerizes to the terminal aldehyde 16 Dihalogenation of alkynes trans configuration addition of two halogens with retention of double bond 17 Radical formation azo compound reagent generates radicals alkenes and HBr with addition of UV light or peroxides give a bromide addition on the least substituted carbon anti Markovnikov addition 18 Sn2 reaction 2nd order collision without intermediates and with 100 inversion tertiary halides do not react due to higher energy transition state from steric hindrance rate depends on concentration of nucleophile has aprotic solvents like THF to prevent solvation interference a Halide nucleophile good leaving groups due to electronegative stabilization same goes for sulfonate esters like benzene sulfonyl due to resonance stabilization proceeds in backside attack Walden inversion from the pentacoordinate transition state b Alkoxide nucleophile product of an alcohol and base reacts with primary and secondary halides to form a Williamson ether synthesis c Amine nucleophile nitrogen displaces the alkyl halide to form an ammonium salt in an acid base reaction secondary amines are more nucleophilic than primary amines while exhaustive methylation leads to multiple products d Phthalimide amine surrogate reaction with sodium amide leads to an amine good nucleophile with alkyl halides and phthalic acid e Azide amine surrogate azide ion N3 and alkyl halide forms an azide alkyl N3 by an Sn2 reaction treatment with NaBH4 yields an amine alkyl NH2 f Cyanide amine surrogate bidentate nucleophile carbon is more nucleophilic if K or Na are used nitrogen is more nucleophilic if others are used forming isonitriles reacts with alkyl halides to form a nitrile alkyl CN replacing the halogen g Phosphine and an alkyl halide substitution of the halogen by phosphine forms a phosphonium salt similar to amines forming an ammonium salt that is more stable than an ammonium salt due to the lack of exhaustive methylation 19 Sn1 reaction 1st order ionization using elimination of chirality due to planar carbocation intermediate with no facial selectivity uses water or aqueous solution for solvation primary halides do not undergo Sn1 reactions due to high transition state less carbocation stability rate of reaction does not depend on nucleophile concentration and alkyl hydride rearrangement can happen a Hydration substitution of an alkyl halide halogen is replaced by an oxonium ion through oxygen nucleophile of H2O which undergoes deprotonation to alcohol OH