organic chem yo

alkene

H2 Ni catalyst ; recduction
alkenes → alkanes

(alkanes) CH4 + = CO2 + 2H2O

[E] O2 ; combustion

(alkanes) [E] CH4 + = CH3X + HX (halogenalkanes)

Limited X2 (Cl/Br) uv light ; FRS

alkene → HALOGENALKANES

HX(g) (Cl/Br/I) rt HI > HBr > HCl ; EA
HI has highest reactivity bc of lowest bond energy

alkene → ALCOHOL

H2O (g), conc H3PO4, high T&P ; EA

alkene → HALOGENALKANES

X2 (Cl/Br) in CCl4, rt ; EA

pale yellow Cl2 decolourise

Orange-red Br2 decolourises

(absence of uv light to avoid FRS)

nt v imporatant

ICl in CCl4, rt ; EA

alkene → HALOGENALKENE & ALCOHOL

Br2 (aq), rt ; EA

orange Br2(aq) decolourises

test of presence of alkene

alkene → DIOL

Dilute KMnO4 (aq), NaOH (aq) COLD ; mild oxidation

……………………..H2SO4 (aq)

alkene → ketone, carb acid, produce CO2

KMnO4 (aq), H2SO4 (aq) Heat ; Oxidative cleavage

Step Down

C=C → C=O

H → OH

R → R

=CH2 → CO2 + H2O

benzene → HALOGENOARANE

X2, anhydrous FeX3 / AlX3 catalyst, rt ; ES

benzene → NITRObenzene

Benzene : conc HNO3, conc H2SO4, 50dc ; ES

alkylbenzene : conc HNO3, conc H2SO4, 30dc ; ES

electron-donating methyl grp 2,4-directing

nt important

conc HNO3, conc H2SO4, >50dc ; ES

COOH is electron-withdrawing grp 3-directing

benzene → ALKYLbenzene

RX (halogenoalkane), anhydrous AlX3 catalyst, rt ; ES

side chain on benzene to -COOH

KMnO4 (aq), H2SO4 (aq) Heat under reflux ; Side chain oxidation

first carbon directly attached to benzene must have at least one H

If alkaline KMnO4, -COOH grp → -COO- (acid base rxn)

Side Products :

R has x1 C, extra CO2 + H2O

R has x2 C, extra CH3COOH

ALKANE (side chain) → halogenalkane

Limited X2 (Cl/Br), uv light ; FRS

Halogenoalkane → alcohol

NaOH (aq), Heat ; NS

KOH (aq)

halogenoalkane → alkene

NaOH in ethanol, heat ; Elimination

Ethanolic KOH

halogenoalkane → AMINE

[E] ethanolic NH3, heated under pressure (heat in sealed tube) ; NS

2 steps :

1. NS of RX → R-NH3+

2. rmv H+ to form R-NH2

amine (not important)

Ethanolic MEDIUM, heated under pressure (heat in sealed tube)

halogenoalkane → -CN (nitrile)

Ethanolic NaCN, heat ; NS

STEP UP RXN

ethanolic KCN can be used

resistance to NS

NaOH (aq) Heat

OR

[E] ethanolic NH3, heat under pressure/sealed tube

OR

ethanolic NaCN heat

partial double bond

additional rsn : hgih electron density of ring repels necleophile

Xtra

conc H2SO4, conc HNO3, >50dc ; ES

electron-withdrawing halogen grp is 2,4-direction

-CN → amine

LiAlH4 (in dry ether) ; Reduction

OR
H2(g), nickel catalyst

-CN → -COO- (deprotonated form)

NaOH (aq), heat ; Alkaline Hydrolysis

to obtain protonated form,

use aqueous acid such as HCl (aq) or H2SO4 (aq) (AB rxn)

-CN → -COOH

HCl (aq), heat ; Acidic Hydrolysis

H2SO4 (aq), heat