ORGANIC CHEMISTRY - mwit.ac.th

1 ORGANIC CHEMISTRY DEPARTMENT OF CHEMISTRY MAHIDOL WITTAYANUSORN SCHOOL ( ) 1 2/2554 1. ORGANIC NH4+NCO- H2 NCONH2 4A 14 4 4

2 C 1 2 3 (single bond) (double bond) (triple bond) C C 4 2 1 C 2 1 1 ( ) 2 2/2554 sp3 sp2 sp 1) sp3 2s 2px 2py 2pz (tetrahedral) CH4 sp3 H s sp3 ( ) 3 2/2554 2) sp2 s p 2 3 (trigonal planar) 120 p ( -bond) sp2 (C2H4)

3 P ( ) 4 2/2554 2) sp s 1 p 1 p 2 sp 180 (ethyne) sp p 2 (dot structure) dash (condensed formula) (bond-line formula) ( ) 5 2/2554 dash formula (condensed formula) (bond-line formula) C4H10 HCCCCHHHHHHHHH CH3CH2CH2CH3 CH3(CH2)2CH3 2- C5H12 HCCCCHHHHHHHHCHHH (CH3)2 CHCH2CH3 C3H6 HCCCHHHHH CH2=CHCH3 C2H6O HCCHHOHHH CH3CH2OH OH C2H4O COHCHHH CH3 CHO ( ) 6 2/2554 dash formula (condensed formula) (bond-line formula)

4 C2H4O2 COCHHHOH C2H4O2 OOH 2 3 3 dash formula 3 C4H10 HCCCCHHHHHHHHH C3H6 HCCCHHHHH C2H6O HCCHHOHHH ( ) 7 2/2554 dash formula 3 C2H2 C6H6 CH4 2 Homolytic cleavage heterolytic cleavage 1) (Homolytic cleavage)

5 1 (free radical) = ( ) 8 2/2554 Br2 (radical reaction) 2) (Heterolytic cleavage) (cation) (anion) Ethoxide anion acetone (cabanion) (cabocation)

6 2-butene carbocation ( ) 9 2/2554 p (hyperconjugation) (conjugation) p p p ( ) 10 2/2554 R tertiary carbocation (3o-carbocation) secondary carbocation (2o-carbocation) primary carbocation (1o-carbocation)

7 Tertiary radical secondary radical primary radical carbanions carbocations radicals 4 1) (substitution reaction) 2) (addition reaction) 3) (elimination reaction) ( ) 11 2/2554 4) (rearrangement reaction) SN1 SN2 E1 E2 r = k[OH-][CH3Cl] OH- OH- (Nucleophile)

8 Leaving group SN2 Substitution, Nucleophilic, bimolecule 2-chloro-2-methylpropane SN2 3o- SN1 (Substitution, Nucleophilic, Unimolecular) ( ) 12 2/2554 SN2 E2 SN2 E2 major product minor product ( ) E1 SN1 SN2 E1 E2 Methyl 1o 2o Neopentyl 3o (30) (1) ( ) ( ) (~0) ( )

9 13 2/2554 SN1 SN2 E1 E2 CH3X RCH2X RR CHX RR R CX Bimolecular reaction SN1/E1 E2 SN2 SN2 [(CH3)3CO-] E2 SN2 I- CN- RCO2- E2 SN1/E1 SN1 (RO-) E2 1) (The effect of hybridization) Ethyne Ethene Ethene Ethane 2s 2p 2s s s sp 50% s ( )

10 14 2/2554 character sp2 s character sp3 s character 25% s character 2) (Inductive effect) F F