University:
Swansea University
Course:
EGA109 | Introductory Organic Chemistry
Academic year:

2023
Views:

144

Pages:

3
Author:

Sanjeev K

CarbocationCarbanionFree Radicalhybridisationsp2spsp2of central C<109.5109.5Bond angle120°-JeomethyTrigonal PlanarNot exactly tetrahedralPyganuidalbut found as pyramiddInductive+ I increases stabilityI increases stability+I increases stabilityEffectno of hyperonjugative formsin creases stabilityincreases stabilitystabilized byhyperconjugationindbing WOH atomshyperonjugationpositive C of car bocation isresonance effectdelocalization d leadstnext to double bond1Resonancedelocatization of charge place takesincreases stabilityresonances leading toincrease in stability.Steric Effectcauses increase in stabilityincreases stabilityStability enhanced+of tertiary C havingas repulsion b/wbulky alkyl groupskulky groups increasbond angle from109.5 to about 120 Reactions1. Combination with an1. Displacementgives either stable productsHanion+ H3C-I(ter mination) or leads toReacts with-rely chargedEIQUCO2Et(III).other radicals leading to13speciesu+ Ieg H2(CH2iththEtO2C CH CO2ELpropagation reactionsM3CR.+R'.R-R'a 2. Addition to multiple bondaddition of Griguard to2CH3 in 13-CM3 +CH=CH2 =2 Elimination of protoncarbonyl group.I Abstraction of another atomunsaturated compoundDonates proton to yieldH=000orgroup usually H+Mo-HH+ RMg-R.TR'H RHHR.H3CCH3HCCCCH3H3CCHomgx2. Addition to multiple bond/I+RR. + CCC RCALabus3. EliminationHKi-t07H2OHH2CHCanother doublenew racheal may as add to+Cth2vinyl phymerizationBrBrH2C=Chl3. Decomposition3. RearrangementsIntermolecular alkylation4. Combin ation withcation4. Rearrangementby carbocationFFCNaOEE FLHiOFUFF DIChb+11M3C-+CHoEtRsecond generated E reachFCFRYYwith = species. leads topolymeni zation reaction5- Rearrangementswithing Base catalysed ConversionRH4yof ethers to secondary or3"alcond++MyLHRLiSRCHCHMO-R'OROHEtherRICH-R'1,2 by dride shift.alcoholOHIHCHStevens Quart. NY sells toH3C+3CH2H3itCuzanimes using strong baseAllytic H RearrangementsthQRBase11N1H3C+HC41]RHRuOEtIArchCUFRCHH3Cthe ELOHH3C-CR'CH+H-R'HthR"R"RH3CR'HOEt